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 5,320 32,362 SH   SOLE   31,862 0 500
ACCENTURE PLC IRELAND SHS CLASS A G1151C101 4,652 24,187 SH   SOLE   23,777 0 410
ALIBABA GROUP HLDG LTD SPONSORED ADS 01609W102 226 1,354 SH   SOLE   1,354 0 0
ALPHABET INC CAP STK CL A 02079K305 9,243 7,569 SH   SOLE   7,501 0 68
ALPHABET INC CAP STK CL C 02079K107 2,522 2,069 SH   SOLE   2,051 0 18
ALTRIA GROUP INC COM 02209S103 276 6,745 SH   SOLE   6,745 0 0
AMARIN CORP PLC SPONS ADR NEW 023111206 152 10,000 SH   SOLE   10,000 0 0
AMERICAN NATL INS CO COM 028591105 204 1,650 SH   SOLE   1,650 0 0
APPLE INC COM 037833100 12,228 54,597 SH   SOLE   54,087 0 510
ARTESIAN RESOURCES CORP CL A 043113208 222 6,000 SH   SOLE   6,000 0 0
AT&T INC COM 00206R102 330 8,730 SH   SOLE   8,730 0 0
AUTOMATIC DATA PROCESSING IN COM 053015103 3,539 21,925 SH   SOLE   21,815 0 110
BANK HAWAII CORP COM 062540109 4,236 49,297 SH   SOLE   48,282 0 1,015
BANK NEW YORK MELLON CORP COM 064058100 329 7,274 SH   SOLE   7,274 0 0
BANK AMER CORP COM 060505104 210 7,200 SH   SOLE   7,200 0 0
BERKSHIRE HATHAWAY INC DEL CL A 084670108 935 3 SH   SOLE   3 0 0
BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 22,685 109,054 SH   SOLE   107,456 0 1,598
BIOGEN INC COM 09062X103 3,960 17,010 SH   SOLE   16,875 0 135
BOOKING HLDGS INC COM 09857L108 11,191 5,702 SH   SOLE   5,637 0 65
BROWN FORMAN CORP CL B 115637209 392 6,248 SH   SOLE   5,989 0 259
CANADIAN NATL RY CO COM 136375102 6,248 69,532 SH   SOLE   68,787 0 745
CHEVRON CORP NEW COM 166764100 297 2,506 SH   SOLE   2,506 0 0
CISCO SYS INC COM 17275R102 3,415 69,106 SH   SOLE   67,926 0 1,180
COCA COLA CO COM 191216100 319 5,865 SH   SOLE   5,865 0 0
COGNIZANT TECHNOLOGY SOLUTIO CLA 192446102 10,435 173,150 SH   SOLE   170,910 0 2,240
CONSOLIDATED WATER CO INC ORD G23773107 173 10,500 SH   SOLE   10,500 0 0
DOMINION ENERGY INC COM 25746U109 149 1,838 SH   SOLE   1,838 0 0
EXXON MOBIL CORP COM 30231G102 543 7,688 SH   SOLE   7,688 0 0
F5 NETWORKS INC COM 315616102 2,002 14,260 SH   SOLE   14,260 0 0
FACEBOOK INC CL A 30303M102 4,324 24,284 SH   SOLE   23,929 0 355
FACTSET RESH SYS INC COM 303075105 3,402 14,003 SH   SOLE   13,768 0 235
FASTENAL CO COM 311900104 7,717 236,203 SH   SOLE   234,238 0 1,965
FEDEX CORP COM 31428X106 137 944 SH   SOLE   944 0 0
GENTEX CORP COM 371901109 5,177 188,021 SH   SOLE   186,306 0 1,715
GENUINE PARTS CO COM 372460105 10,120 101,613 SH   SOLE   100,373 0 1,240
HORMEL FOODS CORP COM 440452100 1,196 27,339 SH   SOLE   27,259 0 80
INGERSOLL-RAND PLC SHS G47791101 145 1,177 SH   SOLE   1,177 0 0
INTERNATIONAL BUSINESS MACHS COM 459200101 140 964 SH   SOLE   944 0 20
INTEL CORP COM 458140100 389 7,546 SH   SOLE   7,546 0 0
JOHNSON & JOHNSON COM 478160104 9,488 73,334 SH   SOLE   72,479 0 855
L3HARRIS TECHNOLOGIES INC COM 502431109 271 1,299 SH   SOLE   1,299 0 0
MASTERCARD INC CL A 57636Q104 8,471 31,192 SH   SOLE   30,967 0 225
MAXIMUS INC COM 577933104 3,105 40,192 SH   SOLE   40,032 0 160
MCDONALDS CORP COM 580135101 587 2,732 SH   SOLE   2,732 0 0
MERCK & CO INC COM 58933Y105 897 10,652 SH   SOLE   10,652 0 0
MICROSOFT CORP COM 594918104 5,426 39,031 SH   SOLE   38,221 0 810
MIDDLESEX WATER CO COM 596680108 212 3,260 SH   SOLE   3,260 0 0
MSC INDL DIRECT INC CL A 553530106 3,688 50,845 SH   SOLE   50,105 0 740
MUELLER WTR PRODS INC COM SER A 624758108 180 16,000 SH   SOLE   16,000 0 0
NIKE INC CL B 654106103 5,543 59,014 SH   SOLE   57,889 0 1,125
OGE ENERGY CORP COM 670837103 272 6,000 SH   SOLE   6,000 0 0
ORACLE CORP COM 68389X105 11,088 201,490 SH   SOLE   198,145 0 3,345
OTTER TAIL CORP COM 689648103 269 5,000 SH   SOLE   5,000 0 0
PAYCHEX INC COM 704326107 3,471 41,936 SH   SOLE   41,571 0 365
PEPSICO INC COM 713448108 8,307 60,592 SH   SOLE   60,027 0 565
PFIZER INC COM 717081103 247 6,881 SH   SOLE   6,881 0 0
PHILIP MORRIS INTL INC COM 718172109 306 4,030 SH   SOLE   4,030 0 0
PROCTER & GAMBLE CO COM 742718109 243 1,955 SH   SOLE   1,955 0 0
PRICE T ROWE GROUP INC COM 74144T108 9,214 80,652 SH   SOLE   79,627 0 1,025
RAYTHEON CO COM NEW 755111507 9,155 46,663 SH   SOLE   45,978 0 685
ROSS STORES INC COM 778296103 5,758 52,420 SH   SOLE   52,200 0 220
ROYAL CARIBBEAN CRUISES LTD COM V7780T103 198 1,825 SH   SOLE   1,825 0 0
SCHWAB STRATEGIC TR INTL EQTY ETF 808524805 311 9,747 SH   SOLE   9,722 0 25
SCHWAB STRATEGIC TR US BRD MKT ETF 808524102 676 9,514 SH   SOLE   9,458 0 56
SCHWAB STRATEGIC TR US SML CAP ETF 808524607 206 2,954 SH   SOLE   2,947 0 7
SCHWAB STRATEGIC TR US MID-CAP ETF 808524508 203 3,586 SH   SOLE   3,576 0 10
STARBUCKS CORP COM 855244109 6,305 71,304 SH   SOLE   70,849 0 455
STRYKER CORP COM 863667101 2,935 13,568 SH   SOLE   13,463 0 105
TD AMERITRADE HLDG CORP COM 87236Y108 6,187 132,480 SH   SOLE   130,660 0 1,820
TEXAS PAC LD TR SUB CTF PROP IT 882610108 442 680 SH   SOLE   680 0 0
TJX COS INC NEW COM 872540109 13,067 234,433 SH   SOLE   231,093 0 3,340
TRACTOR SUPPLY CO COM 892356106 3,343 36,965 SH   SOLE   36,640 0 325
US BANCORP DEL COM NEW 902973304 315 5,700 SH   SOLE   5,700 0 0
ULTA BEAUTY INC COM 90384S303 4,163 16,608 SH   SOLE   16,418 0 190
UNITED PARCEL SERVICE INC CL B 911312106 13,609 113,577 SH   SOLE   111,927 0 1,650
UNITED TECHNOLOGIES CORP COM 913017109 10,884 79,727 SH   SOLE   78,822 0 905
UNITEDHEALTH GROUP INC COM 91324P102 9,031 41,556 SH   SOLE   41,151 0 405
UNIVEST FINANCIAL CORPORATIO COM 915271100 196 7,679 SH   SOLE   7,679 0 0
VSE CORP COM 918284100 3,954 115,979 SH   SOLE   115,979 0 0
WALGREENS BOOTS ALLIANCE INC COM 931427108 5,325 96,272 SH   SOLE   95,107 0 1,165
WALMART INC COM 931142103 335 2,820 SH   SOLE   2,820 0 0
DISNEY WALT CO COM DISNEY 254687106 5,714 43,845 SH   SOLE   43,185 0 660
WELLS FARGO CO NEW COM 949746101 261 5,173 SH   SOLE   5,173 0 0