The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F INFORMATION TABLE
OMB APPROVAL
OMB Number: 3235-0006
Estimated average burden
hours per response: 23.8
COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8
VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER VOTING AUTHORITY
NAME OF ISSUER TITLE OF CLASS CUSIP (x$1000) PRN AMT PRN CALL DISCRETION MANAGER SOLE SHARED NONE
3M CO COM 88579Y101 237,162 1,230,860 SH   SOLE   846,667 0 384,193
AAR CORP COM 000361105 11,901 285,738 SH   SOLE   285,738 0 0
ABBOTT LABS COM 002824100 173,942 1,451,448 SH   SOLE   1,007,703 0 443,745
ABBVIE INC COM 00287Y109 5,654 52,242 SH   SOLE   20,022 0 32,220
ACCENTURE PLC IRELAND SHS CLASS A G1151C101 362 1,310 SH   SOLE   764 0 546
ACTIVISION BLIZZARD INC COM 00507V109 87,831 944,424 SH   SOLE   839,285 0 105,139
ADOBE SYSTEMS INCORPORATED COM 00724F101 807 1,698 SH   SOLE   398 0 1,300
ALLETE INC COM NEW 018522300 2,175 32,378 SH   SOLE   14,770 0 17,608
ALLIANT ENERGY CORP COM 018802108 40,293 743,958 SH   SOLE   614,547 0 129,411
ALPHABET INC CAP STK CL C 02079K107 543,359 262,666 SH   SOLE   223,922 0 38,744
ALPHABET INC CAP STK CL A 02079K305 3,090 1,498 SH   SOLE   1,194 0 304
AMAZON COM INC COM 023135106 180,923 58,474 SH   SOLE   55,089 0 3,385
AMCOR PLC ORD G0250X107 4,542 388,865 SH   SOLE   200,076 0 188,789
AMERICAN EXPRESS CO COM 025816109 113,227 800,533 SH   SOLE   575,825 0 224,708
AMERICAN TOWER CORP NEW COM 03027X100 664 2,778 SH   SOLE   0 0 2,778
AMERIPRISE FINL INC COM 03076C106 549 2,362 SH   SOLE   1,710 0 652
AMETEK INC COM 031100100 308 2,411 SH   SOLE   2,411 0 0
AMGEN INC COM 031162100 2,104 8,455 SH   SOLE   5,734 0 2,721
ANSYS INC COM 03662Q105 230 677 SH   SOLE   0 0 677
APPLE INC COM 037833100 17,958 147,015 SH   SOLE   77,409 0 69,606
APPLIED MATLS INC COM 038222105 739 5,528 SH   SOLE   51 0 5,477
ASSOCIATED BANC CORP COM 045487105 10,004 468,775 SH   SOLE   444,975 0 23,800
AT&T INC COM 00206R102 1,057 34,912 SH   SOLE   11,535 0 23,377
AUTODESK INC COM 052769106 277 998 SH   SOLE   998 0 0
AUTOMATIC DATA PROCESSING IN COM 053015103 1,192 6,327 SH   SOLE   4,227 0 2,100
AXOGEN INC COM 05463X106 553 27,299 SH   SOLE   27,299 0 0
BADGER METER INC COM 056525108 20,036 215,284 SH   SOLE   96,609 0 118,675
BANK NEW YORK MELLON CORP COM 064058100 278 5,888 SH   SOLE   4,883 0 1,005
BAXTER INTL INC COM 071813109 48,873 579,480 SH   SOLE   416,164 0 163,316
BECTON DICKINSON & CO COM 075887109 1,002 4,119 SH   SOLE   2,001 0 2,118
BERKSHIRE HATHAWAY INC DEL CL A 084670108 2,700 7 SH   SOLE   7 0 0
BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 6,345 24,838 SH   SOLE   8,675 0 16,163
BIOGEN INC COM 09062X103 287 1,025 SH   SOLE   750 0 275
BIO-TECHNE CORP COM 09073M104 294,099 770,035 SH   SOLE   619,439 0 150,596
BK OF AMERICA CORP COM 060505104 460 11,879 SH   SOLE   1,314 0 10,565
BLACK HILLS CORP COM 092113109 9,303 139,332 SH   SOLE   138,164 0 1,168
BLACKSTONE GROUP INC COM 09260D107 395 5,300 SH   SOLE   5,300 0 0
BOEING CO COM 097023105 938 3,682 SH   SOLE   3,182 0 500
BP PLC SPONSORED ADR 055622104 240 9,860 SH   SOLE   5,310 0 4,550
BRISTOL-MYERS SQUIBB CO COM 110122108 6,146 97,352 SH   SOLE   38,037 0 59,315
C H ROBINSON WORLDWIDE INC COM NEW 12541W209 125,203 1,311,984 SH   SOLE   1,007,159 0 304,825
CALYXT INC COM 13173L107 1,246 206,977 SH   SOLE   206,977 0 0
CARDIOVASCULAR SYS INC DEL COM 141619106 6,070 158,309 SH   SOLE   158,309 0 0
CARRIER GLOBAL CORPORATION COM 14448C104 302 7,150 SH   SOLE   2,390 0 4,760
CASEYS GEN STORES INC COM 147528103 11,363 52,560 SH   SOLE   52,560 0 0
CATALENT INC COM 148806102 13,104 124,429 SH   SOLE   123,826 0 603
CATERPILLAR INC COM 149123101 2,350 10,135 SH   SOLE   4,784 0 5,351
CHEVRON CORP NEW COM 166764100 8,347 79,656 SH   SOLE   28,093 0 51,563
CINTAS CORP COM 172908105 1,368 4,009 SH   SOLE   1,559 0 2,450
CISCO SYS INC COM 17275R102 1,678 32,444 SH   SOLE   11,598 0 20,846
CMC MATERIALS INC COM 12571T100 16,410 92,821 SH   SOLE   92,821 0 0
COCA COLA CO COM 191216100 1,396 26,481 SH   SOLE   13,051 0 13,430
COMCAST CORP NEW CL A 20030N101 461 8,512 SH   SOLE   4,984 0 3,528
CONOCOPHILLIPS COM 20825C104 1,752 33,070 SH   SOLE   12,216 0 20,854
CORE LABORATORIES N V COM N22717107 2,282 79,263 SH   SOLE   57,685 0 21,578
CORESITE RLTY CORP COM 21870Q105 151,095 1,260,703 SH   SOLE   1,112,132 0 148,571
CORNING INC COM 219350105 75,133 1,726,791 SH   SOLE   1,382,304 0 344,487
COSTCO WHSL CORP NEW COM 22160K105 1,170 3,318 SH   SOLE   1,246 0 2,072
CSX CORP COM 126408103 618 6,414 SH   SOLE   510 0 5,904
CULLEN FROST BANKERS INC COM 229899109 23,800 218,835 SH   SOLE   175,555 0 43,280
CUMMINS INC COM 231021106 255 983 SH   SOLE   0 0 983
CYBEROPTICS CORP COM 232517102 3,261 125,574 SH   SOLE   125,574 0 0
DANAHER CORPORATION COM 235851102 207 921 SH   SOLE   640 0 281
DEERE & CO COM 244199105 351 939 SH   SOLE   112 0 827
DELUXE CORP COM 248019101 1,218 29,033 SH   SOLE   26,224 0 2,809
DIGI INTL INC COM 253798102 49,775 2,621,109 SH   SOLE   2,260,547 0 360,562
DISNEY WALT CO COM 254687106 189,773 1,028,470 SH   SOLE   792,925 0 235,545
DOMINION ENERGY INC COM 25746U109 352 4,632 SH   SOLE   1,250 0 3,382
DONALDSON INC COM 257651109 196,498 3,378,569 SH   SOLE   2,648,244 0 730,325
DUKE ENERGY CORP NEW COM NEW 26441C204 248 2,574 SH   SOLE   1,159 0 1,415
ECOLAB INC COM 278865100 360,251 1,682,865 SH   SOLE   1,356,361 0 326,504
ELANCO ANIMAL HEALTH INC COM 28414H103 37,308 1,266,835 SH   SOLE   984,231 0 282,604
EMERSON ELEC CO COM 291011104 15,667 173,655 SH   SOLE   75,502 0 98,153
ENERPAC TOOL GROUP CORP CL A COM 292765104 8,408 321,884 SH   SOLE   321,884 0 0
ENTERPRISE PRODS PARTNERS L COM 293792107 225 10,200 SH   SOLE   8,600 0 1,600
ENVESTNET INC COM 29404K106 5,081 70,349 SH   SOLE   70,349 0 0
EXELON CORP COM 30161N101 275 6,278 SH   SOLE   278 0 6,000
EXXON MOBIL CORP COM 30231G102 4,279 76,637 SH   SOLE   30,272 0 46,365
FACEBOOK INC CL A 30303M102 787 2,671 SH   SOLE   2,605 0 66
FASTENAL CO COM 311900104 179,138 3,562,802 SH   SOLE   2,705,732 0 857,070
FISERV INC COM 337738108 243,345 2,044,229 SH   SOLE   1,610,887 0 433,342
FLEETCOR TECHNOLOGIES INC COM 339041105 269 1,000 SH   SOLE   0 0 1,000
FORD MTR CO DEL COM 345370860 233 19,000 SH   SOLE   15,000 0 4,000
FULLER H B CO COM 359694106 185,223 2,944,254 SH   SOLE   2,549,150 0 395,104
GENERAC HLDGS INC COM 368736104 31,250 95,435 SH   SOLE   70,115 0 25,320
GENERAL ELECTRIC CO COM 369604103 465 35,438 SH   SOLE   21,538 0 13,900
GENERAL MLS INC COM 370334104 30,466 496,833 SH   SOLE   190,948 0 305,885
GENTHERM INC COM 37253A103 34,086 459,939 SH   SOLE   432,181 0 27,758
GENUINE PARTS CO COM 372460105 225 1,950 SH   SOLE   1,700 0 250
GLACIER BANCORP INC NEW COM 37637Q105 14,719 257,871 SH   SOLE   257,501 0 370
GRACO INC COM 384109104 302,279 4,220,589 SH   SOLE   3,288,777 0 931,812
GREAT WESTERN BANCORP INC COM 391416104 35,758 1,180,528 SH   SOLE   1,122,007 0 58,521
HARLEY DAVIDSON INC COM 412822108 299 7,458 SH   SOLE   7,458 0 0
HAWKINS INC COM 420261109 436 13,000 SH   SOLE   0 0 13,000
HERSHEY CO COM 427866108 11,226 70,980 SH   SOLE   66,895 0 4,085
HOME DEPOT INC COM 437076102 127,389 417,328 SH   SOLE   310,744 0 106,584
HONEYWELL INTL INC COM 438516106 170,124 783,731 SH   SOLE   498,468 0 285,263
HORMEL FOODS CORP COM 440452100 214,310 4,485,356 SH   SOLE   3,602,510 0 882,846
HUB GROUP INC CL A 443320106 6,279 93,328 SH   SOLE   93,328 0 0
HYLIION HOLDINGS CORP COMMON STOCK 449109107 1,084 101,600 SH   SOLE   101,600 0 0
IDEXX LABS INC COM 45168D104 1,666 3,404 SH   SOLE   448 0 2,956
ILLINOIS TOOL WKS INC COM 452308109 410 1,849 SH   SOLE   1,450 0 399
INSPIRE MED SYS INC COM 457730109 15,810 76,379 SH   SOLE   75,154 0 1,225
INTEL CORP COM 458140100 16,009 250,136 SH   SOLE   91,801 0 158,335
INTERNATIONAL BUSINESS MACHS COM 459200101 1,157 8,684 SH   SOLE   4,150 0 4,534
INTRICON CORP COM 46121H109 9,428 367,691 SH   SOLE   367,691 0 0
INVESCO QQQ TR UNIT SER 1 46090E103 401 1,255 SH   SOLE   1,020 0 235
IPG PHOTONICS CORP COM 44980X109 316 1,500 SH   SOLE   0 0 1,500
ISHARES TR CORE S&P500 ETF 464287200 1,430 3,594 SH   SOLE   751 0 2,843
ISHARES TR MSCI EAFE ETF 464287465 329 4,342 SH   SOLE   3,350 0 992
ISHARES TR CORE S&P MCP ETF 464287507 234 900 SH   SOLE   900 0 0
ISHARES TR S&P SML 600 GWT 464287887 424 3,310 SH   SOLE   3,310 0 0
JAMF HLDG CORP COM 47074L105 42,615 1,206,550 SH   SOLE   1,065,670 0 140,880
JOHNSON & JOHNSON COM 478160104 253,126 1,540,163 SH   SOLE   1,189,030 0 351,133
JPMORGAN CHASE & CO COM 46625H100 33,814 222,122 SH   SOLE   151,629 0 70,493
KIMBERLY-CLARK CORP COM 494368103 6,400 46,028 SH   SOLE   15,841 0 30,187
LILLY ELI & CO COM 532457108 127,922 684,734 SH   SOLE   512,904 0 171,830
LITTELFUSE INC COM 537008104 194,942 737,188 SH   SOLE   638,603 0 98,585
LOWES COS INC COM 548661107 1,325 6,969 SH   SOLE   3,151 0 3,818
MARCUS CORP DEL COM 566330106 9,534 476,938 SH   SOLE   476,938 0 0
MASTERCARD INCORPORATED CL A 57636Q104 895 2,515 SH   SOLE   100 0 2,415
MCCORMICK & CO INC COM NON VTG 579780206 241 2,700 SH   SOLE   2,700 0 0
MCDONALDS CORP COM 580135101 3,266 14,573 SH   SOLE   11,262 0 3,311
MDU RES GROUP INC COM 552690109 738 23,358 SH   SOLE   7,658 0 15,700
MEDTRONIC PLC SHS G5960L103 335,579 2,840,761 SH   SOLE   2,334,584 0 506,177
MERCK & CO. INC COM 58933Y105 5,849 75,873 SH   SOLE   32,747 0 43,126
MGP INGREDIENTS INC NEW COM 55303J106 5,388 91,092 SH   SOLE   91,092 0 0
MICROSOFT CORP COM 594918104 479,321 2,033,004 SH   SOLE   1,780,089 0 252,915
MONDELEZ INTL INC CL A 609207105 206 3,516 SH   SOLE   2,385 0 1,131
MOTOROLA SOLUTIONS INC COM NEW 620076307 151,461 805,430 SH   SOLE   701,474 0 103,956
MTS SYS CORP COM 553777103 1,601 27,500 SH   SOLE   9,100 0 18,400
NETFLIX INC COM 64110L106 655 1,255 SH   SOLE   1,255 0 0
NEXTERA ENERGY INC COM 65339F101 464 6,141 SH   SOLE   1,888 0 4,253
NIKE INC CL B 654106103 542 4,082 SH   SOLE   4,082 0 0
NORFOLK SOUTHN CORP COM 655844108 1,188 4,423 SH   SOLE   1,112 0 3,311
NORTHWESTERN CORP COM NEW 668074305 9,045 138,725 SH   SOLE   137,446 0 1,279
NOVARTIS AG SPONSORED ADR 66987V109 216 2,530 SH   SOLE   500 0 2,030
NUVEEN MINN QUALITY MUN INM SHS 670734102 463 31,200 SH   SOLE   0 0 31,200
NVE CORP COM NEW 629445206 18,497 263,870 SH   SOLE   218,453 0 45,417
NVENT ELECTRIC PLC SHS G6700G107 113,553 4,068,557 SH   SOLE   3,486,110 0 582,447
NVIDIA CORPORATION COM 67066G104 214,539 401,810 SH   SOLE   355,885 0 45,925
OLD NATL BANCORP IND COM 680033107 49,356 2,552,034 SH   SOLE   2,244,246 0 307,788
ORACLE CORP COM 68389X105 1,976 28,161 SH   SOLE   6,036 0 22,125
OSHKOSH CORP COM 688239201 18,252 153,815 SH   SOLE   153,815 0 0
OTIS WORLDWIDE CORP COM 68902V107 230 3,360 SH   SOLE   960 0 2,400
PATTERSON COS INC COM 703395103 6,867 214,941 SH   SOLE   204,936 0 10,005
PAYCHEX INC COM 704326107 268 2,730 SH   SOLE   1,742 0 988
PENTAIR PLC SHS G7S00T104 16,406 263,252 SH   SOLE   128,110 0 135,142
PEPSICO INC COM 713448108 2,017 14,256 SH   SOLE   7,674 0 6,582
PFIZER INC COM 717081103 72,837 2,010,417 SH   SOLE   1,514,658 0 495,759
PHILIP MORRIS INTL INC COM 718172109 428 4,823 SH   SOLE   1,698 0 3,125
PHILLIPS 66 COM 718546104 1,049 12,866 SH   SOLE   8,450 0 4,416
PHYSICIANS RLTY TR COM 71943U104 10,286 582,108 SH   SOLE   562,808 0 19,300
PLEXUS CORP COM 729132100 7,967 86,753 SH   SOLE   86,753 0 0
PLUG POWER INC COM NEW 72919P202 358 10,000 SH   SOLE   10,000 0 0
POLARIS INC COM 731068102 267 2,000 SH   SOLE   1,850 0 150
PRINCIPAL FINANCIAL GROUP IN COM 74251V102 133,666 2,229,249 SH   SOLE   1,748,755 0 480,494
PROCTER AND GAMBLE CO COM 742718109 24,743 182,702 SH   SOLE   86,530 0 96,172
PROTO LABS INC COM 743713109 21,341 175,286 SH   SOLE   138,042 0 37,244
PURE CYCLE CORP COM NEW 746228303 159 11,855 SH   SOLE   0 0 11,855
QCR HOLDINGS INC COM 74727A104 6,998 148,208 SH   SOLE   148,208 0 0
QUALCOMM INC COM 747525103 144,902 1,092,861 SH   SOLE   934,582 0 158,279
RAVEN INDS INC COM 754212108 6,102 159,186 SH   SOLE   158,686 0 500
RAYTHEON TECHNOLOGIES CORP COM 75513E101 825 10,676 SH   SOLE   2,974 0 7,702
ROCKWELL AUTOMATION INC COM 773903109 41,842 157,632 SH   SOLE   153,843 0 3,789
SCHLUMBERGER LTD COM 806857108 1,115 41,023 SH   SOLE   10,866 0 30,157
SCHWAB CHARLES CORP COM 808513105 86,915 1,333,461 SH   SOLE   1,084,322 0 249,139
SCHWAB STRATEGIC TR US BRD MKT ETF 808524102 4,388 45,370 SH   SOLE   15,510 0 29,860
SCHWAB STRATEGIC TR INTL EQTY ETF 808524805 1,505 40,000 SH   SOLE   0 0 40,000
SEI INVTS CO COM 784117103 201 3,300 SH   SOLE   0 0 3,300
SELECT SECTOR SPDR TR TECHNOLOGY 81369Y803 458 3,452 SH   SOLE   1,052 0 2,400
SHERWIN WILLIAMS CO COM 824348106 132,153 179,067 SH   SOLE   164,470 0 14,597
SHYFT GROUP INC COM 825698103 640 17,200 SH   SOLE   0 0 17,200
SLEEP NUMBER CORP COM 83125X103 12,567 87,581 SH   SOLE   87,581 0 0
SNAP ON INC COM 833034101 2,989 12,954 SH   SOLE   6,389 0 6,565
SONY CORP SPONSORED ADR 835699307 256 2,415 SH   SOLE   760 0 1,655
SOUTHERN CO COM 842587107 258 4,158 SH   SOLE   1,400 0 2,758
SPDR S&P 500 ETF TR TR UNIT 78462F103 3,577 9,026 SH   SOLE   7,352 0 1,674
SPDR S&P MIDCAP 400 ETF TR UTSER1 S&PDCRP 78467Y107 208 437 SH   SOLE   297 0 140
STARBUCKS CORP COM 855244109 934 8,547 SH   SOLE   8,297 0 250
SURMODICS INC COM 868873100 3,399 60,612 SH   SOLE   60,612 0 0
SYSCO CORP COM 871829107 46,999 596,892 SH   SOLE   511,321 0 85,571
TARGET CORP COM 87612E106 113,078 570,899 SH   SOLE   394,943 0 175,956
TCF FINL CORP COM 872307103 548 11,801 SH   SOLE   6,170 0 5,631
TENNANT CO COM 880345103 132,432 1,657,679 SH   SOLE   1,454,851 0 202,828
TESLA INC COM 88160R101 1,001 1,499 SH   SOLE   999 0 500
TEXAS INSTRS INC COM 882508104 6,199 32,800 SH   SOLE   28,475 0 4,325
THERMO FISHER SCIENTIFIC INC COM 883556102 618 1,355 SH   SOLE   205 0 1,150
TORO CO COM 891092108 280,767 2,722,196 SH   SOLE   2,230,664 0 491,532
TRANE TECHNOLOGIES PLC SHS G8994E103 215 1,299 SH   SOLE   939 0 360
TRAVELERS COMPANIES INC COM 89417E109 17,537 116,601 SH   SOLE   52,449 0 64,152
TUSCAN HLDGS CORP COM 90069K104 825 67,100 SH   SOLE   67,100 0 0
UNION PAC CORP COM 907818108 2,111 9,577 SH   SOLE   3,968 0 5,609
UNITED FIRE GROUP INC COM 910340108 1,422 40,873 SH   SOLE   40,873 0 0
UNITED PARCEL SERVICE INC CL B 911312106 45,392 267,028 SH   SOLE   134,077 0 132,951
UNITEDHEALTH GROUP INC COM 91324P102 341,086 916,725 SH   SOLE   801,519 0 115,206
US BANCORP DEL COM NEW 902973304 379,515 6,861,605 SH   SOLE   5,615,067 0 1,246,538
VANGUARD INDEX FDS GROWTH ETF 922908736 206 803 SH   SOLE   803 0 0
VANGUARD INDEX FDS TOTAL STK MKT 922908769 563 2,724 SH   SOLE   1,147 0 1,577
VANGUARD INTL EQUITY INDEX F FTSE EMR MKT ETF 922042858 205 3,933 SH   SOLE   3,279 0 654
VANGUARD SPECIALIZED FUNDS DIV APP ETF 921908844 482 3,275 SH   SOLE   2,979 0 296
VANGUARD WORLD FDS INF TECH ETF 92204A702 280 780 SH   SOLE   50 0 730
VERICEL CORP COM 92346J108 1,555 28,000 SH   SOLE   28,000 0 0
VERIZON COMMUNICATIONS INC COM 92343V104 5,583 96,006 SH   SOLE   26,210 0 69,796
VISA INC COM CL A 92826C839 224,724 1,061,373 SH   SOLE   910,680 0 150,693
WABTEC COM 929740108 405 5,120 SH   SOLE   4,903 0 217
WALGREENS BOOTS ALLIANCE INC COM 931427108 442 8,050 SH   SOLE   2,050 0 6,000
WALMART INC COM 931142103 693 5,105 SH   SOLE   3,383 0 1,722
WEC ENERGY GROUP INC COM 92939U106 685 7,319 SH   SOLE   4,353 0 2,966
WELLS FARGO CO NEW COM 949746101 167,137 4,277,895 SH   SOLE   3,613,155 0 664,740
WEYERHAEUSER CO MTN BE COM NEW 962166104 803 22,550 SH   SOLE   11,648 0 10,902
WINTRUST FINL CORP COM 97650W108 18,763 247,539 SH   SOLE   247,539 0 0
WORKIVA INC COM CL A 98139A105 38,151 432,260 SH   SOLE   403,502 0 28,758
XCEL ENERGY INC COM 98389B100 15,638 235,119 SH   SOLE   143,936 0 91,183
ZIMMER BIOMET HOLDINGS INC COM 98956P102 56,769 354,631 SH   SOLE   187,091 0 167,540
ZOETIS INC CL A 98978V103 568 3,607 SH   SOLE   1,667 0 1,940