
<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
REGISTRANT'S REPORT ON FORM 10-Q FOR THE THREE MONTHS ENDED APRIL 30, 1998, AND
IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
       
<S>                             <C>                     <C>
<PERIOD-TYPE>                   9-MOS                   3-MOS
<FISCAL-YEAR-END>                          JUL-31-1998             JUL-31-1998
<PERIOD-START>                             AUG-01-1997             FEB-01-1998
<PERIOD-END>                               APR-30-1998             APR-30-1998
<CASH>                                     160,610,044             168,610,044
<SECURITIES>                                10,917,089              10,917,089
<RECEIVABLES>                               40,240,652              40,240,652
<ALLOWANCES>                                         0                       0
<INVENTORY>                                          0                       0
<CURRENT-ASSETS>                           229,860,886             229,860,886
<PP&E>                                      49,977,265              49,977,265
<DEPRECIATION>                                       0                       0
<TOTAL-ASSETS>                             321,906,617             321,906,617
<CURRENT-LIABILITIES>                       39,612,842              39,612,842
<BONDS>                                    100,000,000             100,000,000
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          0                       0
<COMMON>                                       194,907                 194,907
<OTHER-SE>                                 172,562,591             172,562,591
<TOTAL-LIABILITY-AND-EQUITY>               321,906,617             321,906,617
<SALES>                                              0                       0
<TOTAL-REVENUES>                           212,815,337              87,111,571
<CGS>                                                0                       0
<TOTAL-COSTS>                              151,814,495              59,504,684
<OTHER-EXPENSES>                            50,603,294              23,109,306
<LOSS-PROVISION>                                     0                       0
<INTEREST-EXPENSE>                             445,587               (337,806)
<INCOME-PRETAX>                              9,951,961               4,835,387
<INCOME-TAX>                                         0                       0
<INCOME-CONTINUING>                          9,951,961               4,835,387
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                                 9,951,961               4,835,387
<EPS-PRIMARY>                                     0.36                    0.17
<EPS-DILUTED>                                     0.32                    0.15
        

</TABLE>
