<TABLE> <S> <C>

<PAGE>
 
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE BALANCE
SHEETS, OF THE COMPANY AS OF MARCH 31, 1999 (UNAUDITED) AND DECEMBER 31, 1998,
STATEMENTS OF INCOME FOR THE PERIODS ENDED MARCH 31, 1999 AND 1998 (UNAUDITED)
AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
       
<S>                             <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   3-MOS
<FISCAL-YEAR-END>                          DEC-31-1999             DEC-31-1998
<PERIOD-START>                             JAN-01-1999             JAN-01-1998
<PERIOD-END>                               MAR-31-1999             MAR-31-1998
<CASH>                                          17,151                   5,523
<SECURITIES>                                         0                       0
<RECEIVABLES>                                   22,263                  22,149
<ALLOWANCES>                                     1,685                   1,665
<INVENTORY>                                          0                       0
<CURRENT-ASSETS>                                     0                       0
<PP&E>                                       1,829,161                1,810735
<DEPRECIATION>                                  70,678                  61,232
<TOTAL-ASSETS>                               1,904,440               1,871,145
<CURRENT-LIABILITIES>                                0                       0
<BONDS>                                              0                       0
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                    100,000                 100,000
<COMMON>                                           400                     399
<OTHER-SE>                                     731,415                 760,179
<TOTAL-LIABILITY-AND-EQUITY>                 1,904,440               1,871,145
<SALES>                                              0                       0
<TOTAL-REVENUES>                                71,392                  51,373
<CGS>                                                0                       0
<TOTAL-COSTS>                                   52,653                  35,500
<OTHER-EXPENSES>                                     0                       0
<LOSS-PROVISION>                                     0                       0
<INTEREST-EXPENSE>                              13,494                   8,146
<INCOME-PRETAX>                                 17,257                  18,404
<INCOME-TAX>                                         0                       0
<INCOME-CONTINUING>                                  0                       0
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                   8,908
<CHANGES>                                            0                       0
<NET-INCOME>                                    17,257                   9,496
<EPS-PRIMARY>                                      .41                     .23
<EPS-DILUTED>                                      .41                     .23
        

</TABLE>