<TABLE> <S> <C>

<PAGE>
 
<ARTICLE> 7
<LEGEND>
PER SHARE INFORMATION CONTAINED IN THIS SCHEDULE HAS BEEN RESTATED TO CONFORM TO
THE PROVISIONS OF STATEMENT OF FINANCIAL ACCOUNTING STANDARDS NO. 128, "EARNINGS
PER SHARE". SUCH PER SHARE INFORMATION ALSO REFLECTS THE COMPANY'S FEBRUARY 27,
1998 TWO-FOR-ONE STOCK SPLIT.

THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM CONDENSED 
CONSOLIDATED FINANCIAL STATEMENTS AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE 
TO SUCH FINANCIAL STATEMENTS
</LEGEND>
<MULTIPLIER> 1,000
       
<S>                             <C>
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-START>                             JAN-01-1997
<PERIOD-END>                               SEP-30-1997
<DEBT-HELD-FOR-SALE>                                 0
<DEBT-CARRYING-VALUE>                                0
<DEBT-MARKET-VALUE>                                  0
<EQUITIES>                                           0
<MORTGAGE>                                           0
<REAL-ESTATE>                                        0
<TOTAL-INVEST>                                 211,996
<CASH>                                          39,548
<RECOVER-REINSURE>                              18,309
<DEFERRED-ACQUISITION>                           4,697
<TOTAL-ASSETS>                                 323,422
<POLICY-LOSSES>                                112,626
<UNEARNED-PREMIUMS>                             31,097
<POLICY-OTHER>                                       0
<POLICY-HOLDER-FUNDS>                                0
<NOTES-PAYABLE>                                 33,125
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                             0
<OTHER-SE>                                           0
<TOTAL-LIABILITY-AND-EQUITY>                   323,422
<PREMIUMS>                                     116,119
<INVESTMENT-INCOME>                              8,114
<INVESTMENT-GAINS>                              10,022
<OTHER-INCOME>                                  23,910
<BENEFITS>                                      92,220
<UNDERWRITING-AMORTIZATION>                     33,954
<UNDERWRITING-OTHER>                            15,563
<INCOME-PRETAX>                                 16,428
<INCOME-TAX>                                     4,994
<INCOME-CONTINUING>                                  0
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    11,434
<EPS-PRIMARY>                                     0.96
<EPS-DILUTED>                                     0.94
<RESERVE-OPEN>                                       0
<PROVISION-CURRENT>                                  0
<PROVISION-PRIOR>                                    0
<PAYMENTS-CURRENT>                                   0
<PAYMENTS-PRIOR>                                     0
<RESERVE-CLOSE>                                      0
<CUMULATIVE-DEFICIENCY>                              0
        

</TABLE>