<TABLE> <S> <C>

<PAGE>
 
<ARTICLE> 7
       
<S>                             <C>                     <C>
<PERIOD-TYPE>                   YEAR                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1997             DEC-31-1996
<PERIOD-START>                             DEC-31-1996             DEC-31-1995
<PERIOD-END>                               DEC-31-1997             DEC-31-1996
<DEBT-HELD-FOR-SALE>                         1,929,518               2,126,120
<DEBT-CARRYING-VALUE>                                0                       0
<DEBT-MARKET-VALUE>                                  0                       0
<EQUITIES>                                          13                     262
<MORTGAGE>                                           0                       0
<REAL-ESTATE>                                        0                       0
<TOTAL-INVEST>                               2,194,738               2,261,353
<CASH>                                          32,148                   7,176
<RECOVER-REINSURE>                             332,406                 257,983
<DEFERRED-ACQUISITION>                          45,288                  44,006
<TOTAL-ASSETS>                               3,057,258               3,117,516
<POLICY-LOSSES>                              2,003,187               2,091,072
<UNEARNED-PREMIUMS>                            211,455                 205,982
<POLICY-OTHER>                                       0                       0
<POLICY-HOLDER-FUNDS>                           10,200                  12,524
<NOTES-PAYABLE>                                203,000                 204,699
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          0                       0
<COMMON>                                       122,214                 121,716
<OTHER-SE>                                     356,133                 304,112
<TOTAL-LIABILITY-AND-EQUITY>                 3,057,258               3,117,516
<PREMIUMS>                                     375,951                 420,575
<INVESTMENT-INCOME>                            136,698                 133,936
<INVESTMENT-GAINS>                               8,598                   2,984
<OTHER-INCOME>                                  10,311                   9,189
<BENEFITS>                                     307,281                 536,623
<UNDERWRITING-AMORTIZATION>                     93,501                  90,292
<UNDERWRITING-OTHER>                            89,855                 114,111
<INCOME-PRETAX>                                 25,153               (191,394)
<INCOME-TAX>                                     5,400                (56,060)
<INCOME-CONTINUING>                                  0                       0
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                (4,734)                       0
<CHANGES>                                            0                       0
<NET-INCOME>                                    15,019               (135,334)
<EPS-PRIMARY>                                     0.63                  (5.68)
<EPS-DILUTED>                                     0.61                  (5.68)
<RESERVE-OPEN>                                       0                       0
<PROVISION-CURRENT>                                  0                       0
<PROVISION-PRIOR>                                    0                       0
<PAYMENTS-CURRENT>                                   0                       0
<PAYMENTS-PRIOR>                                     0                       0
<RESERVE-CLOSE>                                      0                       0
<CUMULATIVE-DEFICIENCY>                              0                       0
        

</TABLE>