<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM FORM 10-K,
FOR THE YEARS ENDED DECEMBER 31, 1998, 1997 AND 1996 AND IS QUALIFIED IN ITS
ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
<S>                             <C>                     <C>                     <C>
<PERIOD-TYPE>                   12-MOS                   12-MOS                   12-MOS
<FISCAL-YEAR-END>                          DEC-31-1998             DEC-31-1997             DEC-31-1996
<PERIOD-START>                             JAN-01-1998             JAN-01-1997             JAN-01-1996
<PERIOD-END>                               DEC-31-1998             DEC-31-1997             DEC-31-1996
<CASH>                                          51,092                  39,308                   6,729
<SECURITIES>                                         0                       0                       0
<RECEIVABLES>                                   53,725                  36,411                  26,157
<ALLOWANCES>                                   (8,400)                 (8,912)                 (9,157)
<INVENTORY>                                          0                       0                       0
<CURRENT-ASSETS>                                     0                       0                       0
<PP&E>                                       3,643,770               1,793,327               1,172,034
<DEPRECIATION>                               (340,727)               (236,220)               (110,260)
<TOTAL-ASSETS>                               3,820,639               1,969,630               1,341,854
<CURRENT-LIABILITIES>                                0                       0                       0
<BONDS>                                      2,641,015               1,107,425                 770,625
<PREFERRED-MANDATORY>                                0                       0                       0
<PREFERRED>                                    396,000                 121,000                  94,000
<COMMON>                                           731                     731                     527
<OTHER-SE>                                     624,388                 648,649                 424,003
<TOTAL-LIABILITY-AND-EQUITY>                 3,820,639               1,969,630               1,341,854
<SALES>                                              0                       0                       0
<TOTAL-REVENUES>                               328,465                 216,808                 158,526
<CGS>                                                0                       0                       0
<TOTAL-COSTS>                                  188,208                 123,092                  92,534
<OTHER-EXPENSES>                                 4,257                   2,478                   1,063
<LOSS-PROVISION>                                     0                       0                       0
<INTEREST-EXPENSE>                             106,852                  57,472                  40,233
<INCOME-PRETAX>                                106,188                  46,865                  24,696
<INCOME-TAX>                                         0                       0                       0
<INCOME-CONTINUING>                             53,293                  46,865                  24,696
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                 53,895                       0                       0
<CHANGES>                                            0                       0                       0
<NET-INCOME>                                   106,188                  46,865                  24,696
<EPS-PRIMARY>                                     1.21                    0.54                    0.42
<EPS-DILUTED>                                     1.20                    0.54                    0.42
        

</TABLE>