<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM COMPANY'S
CONDENSED CONSOLIDATED BALANCE SHEET AND STATEMENT OF INCOME TAXES AND IS
QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
<S>                             <C>                     <C>
<PERIOD-TYPE>                   9-MOS                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1996             DEC-31-1995
<PERIOD-START>                             JAN-01-1996             JAN-01-1995
<PERIOD-END>                               SEP-30-1996             SEP-30-1995
<CASH>                                          12,890                  10,320
<SECURITIES>                                    81,008                   6,035
<RECEIVABLES>                                   37,490                  30,713
<ALLOWANCES>                                     (650)                   (513)
<INVENTORY>                                          0                       0
<CURRENT-ASSETS>                               133,878                  48,580
<PP&E>                                          30,813                  28,981
<DEPRECIATION>                                  14,621                  13,612
<TOTAL-ASSETS>                                 151,238                  76,649
<CURRENT-LIABILITIES>                           26,162                  15,521
<BONDS>                                          2,700                   2,900
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          0                       0
<COMMON>                                           209                     157
<OTHER-SE>                                     120,545                  56,984
<TOTAL-LIABILITY-AND-EQUITY>                   151,238                  76,649
<SALES>                                         22,964                  18,783
<TOTAL-REVENUES>                               115,015                  94,793
<CGS>                                           18,063                  14,546
<TOTAL-COSTS>                                  100,208                  84,232
<OTHER-EXPENSES>                                     0                       0
<LOSS-PROVISION>                                    90                     265
<INTEREST-EXPENSE>                                 109                     188
<INCOME-PRETAX>                                 17,730                  11,499
<INCOME-TAX>                                     7,092                     605
<INCOME-CONTINUING>                             10,638                  10,894
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                                    10,638                  10,894
<EPS-PRIMARY>                                      .50                     .40
<EPS-DILUTED>                                      .50                     .40
        

</TABLE>