<TABLE> <S> <C>

<PAGE>

<ARTICLE> 5
<RESTATED>

<S>                             <C>                     <C>                     <C>
<PERIOD-TYPE>                   12-MOS                   9-MOS                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1996             DEC-31-1996             DEC-31-1996
<PERIOD-START>                             JAN-01-1996             JAN-01-1996             JAN-01-1996
<PERIOD-END>                               DEC-31-1996             SEP-30-1996             JUN-30-1996
<CASH>                                       2,575,350               1,920,965               2,199,931
<SECURITIES>                                12,878,526              12,146,063               9,703,654
<RECEIVABLES>                                4,798,919               4,449,773               4,041,155
<ALLOWANCES>                                   388,471                   8,570                 107,891
<INVENTORY>                                  4,035,175               4,168,245               4,455,355
<CURRENT-ASSETS>                            24,914,572              23,246,903              20,441,266
<PP&E>                                       9,581,726               9,183,941               8,244,133
<DEPRECIATION>                               3,873,975               3,411,316               2,971,936
<TOTAL-ASSETS>                              36,809,107              34,921,284              31,614,219
<CURRENT-LIABILITIES>                        9,219,598              10,002,546               8,960,336
<BONDS>                                              0                       0                       0
<PREFERRED-MANDATORY>                                0                       0                       0
<PREFERRED>                                          0                       0                       0
<COMMON>                                         6,842                   6,744                   6,711
<OTHER-SE>                                  26,322,740              23,463,587              21,193,290
<TOTAL-LIABILITY-AND-EQUITY>                36,809,107              34,921,284              31,614,219
<SALES>                                     40,152,897              28,061,885              17,542,763
<TOTAL-REVENUES>                            40,152,897              28,061,885              17,542,763
<CGS>                                       21,819,544              15,811,719              10,133,730
<TOTAL-COSTS>                               33,316,273              23,823,913              15,269,909
<OTHER-EXPENSES>                                38,389                  37,999                  37,999
<LOSS-PROVISION>                                     0                       0                       0
<INTEREST-EXPENSE>                             210,314                 151,599                  94,135
<INCOME-PRETAX>                              7,293,420               4,561,983               2,482,774
<INCOME-TAX>                                   231,000                 140,000                 166,300
<INCOME-CONTINUING>                          7,062,420               4,421,983               2,316,474
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0
<CHANGES>                                            0                       0                       0
<NET-INCOME>                                 7,062,420               4,421,983               2,316,474
<EPS-PRIMARY>                                     1.06<F1>                    0.67<F1>                    0.35<F1>
<EPS-DILUTED>                                     0.96<F2>                    0.60<F2>                    0.32<F2>
<FN>
<F1>EPS - Basic Per SFAS No. 128
<F2>EPS - Diluted Per SFAS No. 128
</FN>



</TABLE>