<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE BALANCE
SHEETS OF THE COMPANY AS OF SEPTEMBER 30, 2000 (UNAUDITED) AND DECEMBER 31,
1999, STATEMENTS OF INCOME FOR THE PERIODS ENDED SEPTEMBER 30, 2000 AND 1999
(UNAUDITED) AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL
STATEMENTS.
</LEGEND>

<S>                             <C>                     <C>
<PERIOD-TYPE>                   9-MOS                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-2000             DEC-31-1999
<PERIOD-START>                             JAN-01-2000             JAN-01-1999
<PERIOD-END>                               SEP-30-2000             SEP-30-1999
<CASH>                                           4,935                  13,313
<SECURITIES>                                         0                       0
<RECEIVABLES>                                   38,345                  31,167
<ALLOWANCES>                                     3,952                   2,890
<INVENTORY>                                          0                       0
<CURRENT-ASSETS>                                     0                       0
<PP&E>                                       1,994,361               1,898,482
<DEPRECIATION>                                 116,703                  91,461
<TOTAL-ASSETS>                               2,096,896               1,994,663
<CURRENT-LIABILITIES>                                0                       0
<BONDS>                                              0                       0
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                    100,000                 100,000
<COMMON>                                           405                     401
<OTHER-SE>                                     705,410                 731,092
<TOTAL-LIABILITY-AND-EQUITY>                 2,096,896               1,994,663
<SALES>                                              0                       0
<TOTAL-REVENUES>                               250,809                 221,983
<CGS>                                                0                       0
<TOTAL-COSTS>                                  193,011                 167,710
<OTHER-EXPENSES>                                     0                       0
<LOSS-PROVISION>                                     0                       0
<INTEREST-EXPENSE>                              53,092                  44,325
<INCOME-PRETAX>                                 53,040                  50,852
<INCOME-TAX>                                         0                       0
<INCOME-CONTINUING>                                  0                       0
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                                    53,040                  50,852
<EPS-BASIC>                                       1.32                    1.21
<EPS-DILUTED>                                     1.31                    1.21


</TABLE>