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
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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
2U, Inc. COM 90214J101 87,595 1,042,421 SH   SOLE   736,906 0 305,515
3M Company COM 88579Y101 24,590 112,015 SH   SOLE   110,447 0 1,568
A. O. Smith Corporation COM 831865209 45,903 721,851 SH   SOLE   560,355 0 161,496
Acuity Brands, Inc. COM 00508Y102 44,381 318,850 SH   SOLE   252,757 0 66,093
Agco Corp Com COM 001084102 224 3,457 SH   SOLE   3,457 0 0
Alarm.com Holdings, Inc. COM 011642105 46,356 1,228,298 SH   SOLE   864,885 0 363,413
Alphabet, Inc. Class A COM 02079K305 21,680 20,904 SH   SOLE   18,966 0 1,938
Alphabet, Inc. Class C COM 02079K107 18,579 18,007 SH   SOLE   17,536 0 471
Amazon.com, Inc. COM 023135106 66,621 46,030 SH   SOLE   43,540 0 2,490
Analog Devices, Inc. COM 032654105 30,064 329,897 SH   SOLE   317,006 0 12,891
Ansys, Inc. COM 03662Q105 86,741 553,581 SH   SOLE   411,933 0 141,648
Apple Inc. COM 037833100 7,190 42,854 SH   SOLE   33,704 0 9,150
AT&T Inc. COM 00206R102 203 5,708 SH   SOLE   4,400 0 1,308
athenahealth, Inc. COM 04685W103 134,694 941,719 SH   SOLE   723,110 0 218,609
Beacon Roofing Supply, Inc. COM 073685109 70,399 1,326,537 SH   SOLE   1,008,772 0 317,765
Berkshire Hathaway Inc. Class COM 084670702 328 1,645 SH   SOLE   1,070 0 575
Bio-Techne Corporation COM 09073M104 80,106 530,364 SH   SOLE   364,814 0 165,550
BlackLine, Inc. COM 09239B109 34,413 877,659 SH   SOLE   665,230 0 212,429
Boeing Co Com COM 097023105 278 849 SH   SOLE   749 0 100
Bristol-Myers Squibb Company COM 110122108 368 5,825 SH   SOLE   5,825 0 0
Cabot Microelectronics Corpora COM 12709P103 26,373 246,221 SH   SOLE   185,704 0 60,517
Calavo Growers, Inc. COM 128246105 41,828 453,663 SH   SOLE   343,331 0 110,332
Cardinal Health, Inc. COM 14149y108 1,900 30,315 SH   SOLE   30,315 0 0
Cass Information Systems, Inc. COM 14808P109 22,884 384,533 SH   SOLE   290,970 0 93,563
Cerner Corporation COM 156782104 17,116 295,112 SH   SOLE   280,751 0 14,361
Cheesecake Factory, Inc. COM 163072101 19,748 409,531 SH   SOLE   307,702 0 101,829
Chemed Corporation COM 16359R103 147,532 540,687 SH   SOLE   406,394 0 134,293
Cisco Systems, Inc. COM 17275R102 24,683 575,491 SH   SOLE   570,980 0 4,511
Coca-Cola Company COM 191216100 248 5,704 SH   SOLE   4,704 0 1,000
Cognex Corporation COM 192422103 19,521 375,470 SH   SOLE   228,736 0 146,734
Colgate-Palmolive Company COM 194162103 2,563 35,763 SH   SOLE   35,763 0 0
CoStar Group, Inc. COM 22160N109 114,739 316,365 SH   SOLE   245,113 0 71,252
Cree, Inc. COM 225447101 1,852 45,949 SH   SOLE   24,212 0 21,737
Digi International, Inc. COM 253798102 13,694 1,329,560 SH   SOLE   1,026,590 0 302,970
Diplomat Pharmacy, Inc. COM 25456K101 12,169 603,899 SH   SOLE   455,290 0 148,609
Dorman Products, Inc. COM 258278100 47,686 720,218 SH   SOLE   493,910 0 226,308
Ecolab, Inc. COM 278865100 49,452 360,779 SH   SOLE   343,766 0 17,013
Ellie Mae, Inc. COM 28849P100 59,389 645,956 SH   SOLE   454,496 0 191,460
Equifax, Inc. COM 294429105 1,826 15,496 SH   SOLE   15,496 0 0
Evolent Health, Inc. Class A COM 30050B101 40,131 2,816,223 SH   SOLE   2,143,239 0 672,984
ExlService Holdings, Inc. COM 302081104 50,249 901,002 SH   SOLE   619,656 0 281,346
Exponent, Inc. COM 30214u102 33,930 431,411 SH   SOLE   326,529 0 104,882
Fastenal Company COM 311900104 98,873 1,811,197 SH   SOLE   1,409,822 0 401,375
Financial Engines, Inc. COM 317485100 27,604 788,684 SH   SOLE   595,485 0 193,199
Fiserv, Inc. COM 337738108 64,660 906,752 SH   SOLE   864,091 0 42,661
Five Below, Inc. COM 33829M101 147,050 2,005,045 SH   SOLE   1,508,549 0 496,496
Freshpet, Inc. COM 358039105 28,891 1,756,279 SH   SOLE   1,325,252 0 431,027
Gentex Corporation COM 371901109 117,022 5,083,497 SH   SOLE   3,899,108 0 1,184,389
Globant S.A. COM L44385109 81,129 1,574,107 SH   SOLE   1,206,004 0 368,103
GoDaddy, Inc. Class A COM 380237107 32,111 522,814 SH   SOLE   324,985 0 197,829
Grand Canyon Education, Inc. COM 38526M106 224,058 2,135,513 SH   SOLE   1,641,510 0 494,003
Healthcare Services Group, Inc COM 421906108 125,531 2,887,095 SH   SOLE   2,168,533 0 718,562
Healthstream, Inc. COM 42222N103 46,661 1,879,218 SH   SOLE   1,316,887 0 562,331
HEICO Corporation COM 422806109 159,796 1,840,753 SH   SOLE   1,369,125 0 471,628
Henry Schein, Inc. COM 806407102 29,006 431,580 SH   SOLE   333,917 0 97,663
Heska Corporation COM 42805e306 30,664 387,810 SH   SOLE   294,366 0 93,444
IHS Markit Ltd. COM G47567105 76,553 1,586,912 SH   SOLE   1,241,742 0 345,170
Illinois Tool Works Inc. COM 452308109 317 2,021 SH   SOLE   2,021 0 0
Illumina, Inc. COM 452327109 219 925 SH   SOLE   925 0 0
InnerWorkings, Inc. COM 45773Y105 10,981 1,213,322 SH   SOLE   913,215 0 300,107
Inovalon Holdings, Inc. Class COM 45781D101 20,274 1,912,655 SH   SOLE   1,613,990 0 298,665
Intel Corporation COM 458140100 3,628 69,653 SH   SOLE   65,997 0 3,656
International Flavors & Fragra COM 459506101 43,509 317,792 SH   SOLE   249,473 0 68,319
Ishares Core S&P 500 Etf COM 464287200 606 2,285 SH   SOLE   2,285 0 0
iShares Core S&P U.S. Growth E COM 464287671 282 5,156 SH   SOLE   1,334 0 3,822
Ishares Tr Russell 1000 COM 464287622 572 3,896 SH   SOLE   3,896 0 0
Ishares Tr Russell 2000 COM 464287655 569 3,749 SH   SOLE   3,749 0 0
Ishares Tr Russell 2000 Growth COM 464287648 226 1,188 SH   SOLE   0 0 1,188
Johnson & Johnson COM 478160104 3,626 28,299 SH   SOLE   27,521 0 778
JPMorgan Chase & Co. COM 46625H100 1,163 10,575 SH   SOLE   9,465 0 1,110
Knight-Swift Transportation Ho COM 499049104 59,970 1,303,404 SH   SOLE   915,974 0 387,430
LKQ Corporation COM 501889208 57,628 1,518,525 SH   SOLE   1,128,839 0 389,686
MAXIMUS, Inc. COM 577933104 68,920 1,032,658 SH   SOLE   718,177 0 314,481
Mednax, Inc. COM 58502B106 46,643 838,457 SH   SOLE   657,601 0 180,856
Medtronic plc COM G5960L103 18,975 236,539 SH   SOLE   88,003 0 148,536
Microsoft Corporation COM 594918104 78,193 856,721 SH   SOLE   820,490 0 36,231
Middleby Corporation COM 596278101 29,466 238,034 SH   SOLE   143,046 0 94,988
Mobile Mini, Inc. COM 60740F105 55,062 1,265,796 SH   SOLE   956,426 0 309,370
National Instruments Corporati COM 636518102 169,812 3,357,952 SH   SOLE   2,616,007 0 741,945
Neogen Corporation COM 640491106 67,603 1,009,149 SH   SOLE   769,785 0 239,364
Oracle Corporation COM 68389X105 229 5,000 SH   SOLE   5,000 0 0
Paccar Inc. COM 693718108 380 5,743 SH   SOLE   5,743 0 0
Patterson Companies, Inc. COM 703395103 707 31,788 SH   SOLE   31,788 0 0
Paychex, Inc. COM 704326107 2,329 37,814 SH   SOLE   37,814 0 0
Paylocity Holding Corp. COM 70438v106 35,728 697,409 SH   SOLE   526,117 0 171,292
Pegasystems, Inc. COM 705573103 62,480 1,030,177 SH   SOLE   776,753 0 253,424
PepsiCo, Inc. COM 713448108 3,990 36,551 SH   SOLE   36,551 0 0
Power Integrations, Inc. COM 739276103 32,177 470,770 SH   SOLE   347,341 0 123,429
PRA Group, Inc. COM 69354N106 102,724 2,703,272 SH   SOLE   2,041,319 0 661,953
Praxair, Inc. COM 74005P104 24,650 170,827 SH   SOLE   164,677 0 6,150
Procter & Gamble Company COM 742718109 2,015 25,412 SH   SOLE   25,412 0 0
Pros Holdings, Inc. COM 74346Y103 84,009 2,544,945 SH   SOLE   1,750,120 0 794,825
Proto Labs, Inc. COM 743713109 209,778 1,784,583 SH   SOLE   1,388,530 0 396,053
Reckitt Benckiser Group ADR COM 756255204 16,277 961,464 SH   SOLE   951,760 0 9,704
Ritchie Bros. Auctioneers, Inc COM 767744105 157,621 5,008,607 SH   SOLE   3,884,299 0 1,124,308
Roche Holding Ltd. ADR COM 771195104 22,430 784,263 SH   SOLE   749,614 0 34,649
Rollins, Inc. COM 775711104 81,953 1,605,980 SH   SOLE   1,284,789 0 321,191
Salesforce.com, Inc. COM 79466L302 40,804 350,853 SH   SOLE   331,972 0 18,881
Schlumberger NV COM 806857108 2,418 37,325 SH   SOLE   37,325 0 0
Snap-on, Inc. COM 833034101 48,597 329,385 SH   SOLE   264,491 0 64,894
Spdr S&P 500 Etf COM 78462F103 622 2,363 SH   SOLE   2,363 0 0
SPS Commerce, Inc. COM 78463M107 41,656 650,158 SH   SOLE   490,955 0 159,203
Starbucks Corporation COM 855244109 47,820 826,041 SH   SOLE   787,750 0 38,291
Stryker Corp Com COM 863667101 306 1,900 SH   SOLE   1,900 0 0
Target Corporation COM 87612E106 1,171 16,863 SH   SOLE   16,745 0 118
Teladoc, Inc. COM 87918A105 35,672 885,159 SH   SOLE   677,577 0 207,582
Tyler Technologies, Inc. COM 902252105 51,590 244,547 SH   SOLE   188,226 0 56,321
U.S. Bancorp COM 902973304 2,180 43,170 SH   SOLE   43,170 0 0
U.S. Physical Therapy, Inc. COM 90337L108 27,599 339,471 SH   SOLE   258,937 0 80,534
Ultimate Software Group, Inc. COM 90385D107 162,257 665,805 SH   SOLE   494,262 0 171,543
United Natural Foods, Inc. COM 911163103 66,982 1,559,904 SH   SOLE   1,117,765 0 442,139
UnitedHealth Group, Inc. COM 91324P102 41,885 195,725 SH   SOLE   184,265 0 11,460
Veeva Systems, Inc. Class A COM 922475108 109,406 1,498,307 SH   SOLE   1,106,871 0 391,436
Verint Systems, Inc. COM 92343X100 25,062 588,316 SH   SOLE   443,851 0 144,465
Verisk Analytics, Inc. COM 92345Y106 94,748 911,039 SH   SOLE   691,894 0 219,145
Visa, Inc. COM 92826C839 23,910 199,881 SH   SOLE   189,448 0 10,433
WABCO Holdings, Inc. COM 92927K102 23,803 177,808 SH   SOLE   109,508 0 68,300
WageWorks, Inc. COM 930427109 51,767 1,145,296 SH   SOLE   802,921 0 342,375
Walgreens Boots Alliance, Inc. COM 931427108 30,498 465,831 SH   SOLE   450,113 0 15,718
Walmart, Inc. COM 931142103 2,463 27,683 SH   SOLE   27,683 0 0
Watsco, Inc. COM 942622200 28,589 157,976 SH   SOLE   102,637 0 55,339
Wells Fargo & Company COM 949746101 353 6,731 SH   SOLE   4,040 0 2,691
West Pharmaceutical Services, COM 955306105 43,192 489,206 SH   SOLE   376,896 0 112,310
Workiva, Inc. Class A COM 98139A105 30,963 1,306,459 SH   SOLE   988,727 0 317,732
Dodge & Cox Stk Fd Com COM 256219106 404 2,050 SH   SOLE   434 0 1,616
Fidelity Concord Str T Sp 500 COM 315911701 1,635 17,628 SH   SOLE   14,750 0 2,878
Growth Fd Amer Inc Com COM 399874106 421 8,255 SH   SOLE   8,255 0 0
JPMORGAN TR II LARGE CAP GR A COM 4812C0506 260 6,572 SH   SOLE   6,572 0 0
RB All Cap Growth Fund Investo COM 46141P305 496 26,606 SH   SOLE   26,606 0 0
Riverbridge Growth Fund - Inst COM 46141P404 8,796 465,390 SH   SOLE   465,390 0 0
Third Ave Tr Real Estate Fd COM 884116401 248 7,376 SH   SOLE   7,376 0 0
Vanguard Index Tr 500 Index Ad COM 922908710 6,602 27,078 SH   SOLE   0 0 27,078
Vanguard Index Trust 500 Index COM 922908108 3,443 14,123 SH   SOLE   10,277 0 3,846