<TABLE> <S> <C>

<PAGE>
<ARTICLE> 9
       
<S>                             <C>                     <C>                     <C>                     <C>
<PERIOD-TYPE>                   YEAR                   3-MOS                   3-MOS                   3-MOS
<FISCAL-YEAR-END>                          DEC-31-1997             MAR-31-1997             JUN-30-1997             SEP-30-1997
<PERIOD-START>                             JAN-01-1997             JAN-01-1997             APR-01-1997             JUL-01-1997
<PERIOD-END>                               DEC-31-1997             MAR-01-1997             JUN-30-1997             SEP-30-1997
<CASH>                                      17,298,566              23,089,795               9,700,841              25,205,303
<INT-BEARING-DEPOSITS>                               0                       0                       0                       0
<FED-FUNDS-SOLD>                            75,000,000                       0              63,000,000                       0
<TRADING-ASSETS>                                     0                       0                       0                       0
<INVESTMENTS-HELD-FOR-SALE>                462,850,089             304,235,614             324,279,512             460,281,597
<INVESTMENTS-CARRYING>                     802,046,077             652,449,979             716,907,576             749,448,367
<INVESTMENTS-MARKET>                       809,708,389             648,999,683             719,500,877             757,781,734
<LOANS>                                     56,044,957              76,708,227             102,527,199              47,503,504
<ALLOWANCE>                                    100,000                 100,000                 100,000                 100,000
<TOTAL-ASSETS>                           1,460,446,776           1,095,336,047           1,257,865,445           1,332,482,156
<DEPOSITS>                                 846,739,932             623,790,739             740,951,179             551,694,613
<SHORT-TERM>                               499,932,628             365,181,507             409,123,917             672,444,111
<LIABILITIES-OTHER>                         13,899,936              16,882,965              14,554,103              11,912,498
<LONG-TERM>                                          0                       0                       0                       0
<PREFERRED-MANDATORY>                       24,161,104              24,244,743              24,216,332              24,166,257
<PREFERRED>                                          0                       0                       0                       0
<COMMON>                                        66,643                  66,806                  66,395                  66,395
<OTHER-SE>                                  75,646,533              65,169,287              68,953,520              72,198,282
<TOTAL-LIABILITIES-AND-EQUITY>           1,460,446,776           1,095,336,047           1,257,865,445           1,332,482,156
<INTEREST-LOAN>                              2,566,321                 664,409                 675,886                 570,264
<INTEREST-INVEST>                           70,469,608              14,367,193              16,316,033              18,547,320
<INTEREST-OTHER>                                     0                       0                       0                       0
<INTEREST-TOTAL>                            73,035,929              15,031,602              16,991,919              19,117,584
<INTEREST-DEPOSIT>                          18,722,500               4,445,602               5,014,000               4,408,706
<INTEREST-EXPENSE>                          46,863,231               8,575,466              10,402,357              13,020,232
<INTEREST-INCOME-NET>                       26,172,698               6,456,136               6,589,562               6,097,352
<LOAN-LOSSES>                                        0                       0                       0                       0
<SECURITIES-GAINS>                             113,958                       0                   7,110                  34,650
<EXPENSE-OTHER>                             87,362,391              20,252,299              20,976,977              21,752,152
<INCOME-PRETAX>                             21,448,608               5,095,308               5,244,658               5,405,164
<INCOME-PRE-EXTRAORDINARY>                  21,448,608               5,095,308               5,244,658               5,405,164
<EXTRAORDINARY>                                      0                       0                       0                       0
<CHANGES>                                            0                       0                       0                       0
<NET-INCOME>                                12,629,880               3,009,229               3,092,317               3,133,551
<EPS-PRIMARY>                                     1.90                    0.45                    0.47                    0.47
<EPS-DILUTED>                                     1.85                    0.44                    0.46                    0.46
<YIELD-ACTUAL>                                    2.24                    2.71                    2.60                    2.38
<LOANS-NON>                                          0                       0                       0                       0
<LOANS-PAST>                                         0                       0                       0                       0
<LOANS-TROUBLED>                                     0                       0                       0                       0
<LOANS-PROBLEM>                                      0                       0                       0                       0
<ALLOWANCE-OPEN>                               100,000                 100,000                 100,000                 100,000
<CHARGE-OFFS>                                        0                       0                       0                       0
<RECOVERIES>                                         0                       0                       0                       0
<ALLOWANCE-CLOSE>                              100,000                 100,000                 100,000                 100,000
<ALLOWANCE-DOMESTIC>                           100,000                 100,000                 100,000                 100,000
<ALLOWANCE-FOREIGN>                                  0                       0                       0                       0
<ALLOWANCE-UNALLOCATED>                              0                       0                       0                       0
        

</TABLE>