<TABLE> <S> <C>


<ARTICLE>                     5
<LEGEND>
THIS  SCHEDULE  CONTAINS  SUMMARY  FINANCIAL   INFORMATION  EXTRACTED  FROM  THE
CONSOLIDATED  BALANCE SHEETS AS OF MARCH 31, 1997,  JUNE 30, 1997, AND SEPTEMBER
30, 1997 AND THE RELATED  CONSOLIDATED  STATEMENTS OF INCOME AND IS QUALIFIED IN
ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS. THE INFORMATION PROVIDED
FOR THE THREE MONTHS ENDED MARCH 31,1997, THE SIX MONTHS ENDED JUNE 30, 1997 AND
THE NINE MONTHS ENDED SEPTEMBER 30, 1997 HAS BEEN RESTATED PURSUANT TO STATEMENT
OF FINANCIAL  ACCOUNTING STANDARDS NO. 128, EARNINGS PER SHARE ("SFAS N0. 128").
THIS  SCHEDULE IS  QUALIFIED  IN ITS  ENTIRETY BY  REFERENCE  TO SUCH  FINANCIAL
STATEMENTS. THIS EXHIBIT SHALL NOT BE DEEMED FILED FOR THE PURPOSE OF SECTION 11
OF THE SECURITIES  ACT OF 1933 AND SECTION 18 OF THE SECURITIES  EXCHANGE ACT OF
1934, OR OTHERWISE  SUBJECT TO THE LIABILITY OF SUCH  SECTIONS,  NOR SHALL IT BE
DEEMED A PART OF ANY OTHER FILING WHICH  INCORPORATES  THIS REPORT BY REFERENCE,
UNLESS SUCH OTHER FILING EXPRESSLY INCORPORATES THIS EXHIBIT BY REFERENCE.
</LEGEND>
<RESTATED>
<MULTIPLIER>                  1,000
<CURRENCY>                    U.S. Dollars
       
<S>                               <C>                        <C>                       <C>
<PERIOD-TYPE>                       3-MOS                      6-MOS                     9-MOS
<FISCAL-YEAR-END>               DEC-31-1997                DEC-31-1997               DEC-31-1997
<PERIOD-START>                  JAN-01-1997                JAN-01-1997               JAN-01-1997
<PERIOD-END>                    MAR-31-1997                JUN-30-1997               SEP-30-1997
<EXCHANGE-RATE>                           1                          1                         1
<CASH>                                5,660                      3,330                     1,424
<SECURITIES>                              0                          0                         0
<RECEIVABLES>                        25,076                     24,902                    25,679
<ALLOWANCES>                          1,200                      1,700                     2,200
<INVENTORY>                               0                          0                         0
<CURRENT-ASSETS>                          0                          0                         0
<PP&E>                              860,681                    873,555                   928,234
<DEPRECIATION>                      172,016                    171,174                   173,981
<TOTAL-ASSETS>                    1,105,361                    917,397                   999,302
<CURRENT-LIABILITIES>                     0                          0                         0
<BONDS>                             569,519                    382,083                   435,646
<PREFERRED-MANDATORY>                     0                          0                         0
<PREFERRED>                               0                          0                         0
<COMMON>                                406                        407                       417
<OTHER-SE>                          496,707                    501,227                   523,599
<TOTAL-LIABILITY-AND-EQUITY>      1,105,361                    917,397                   999,302
<SALES>                                   0                          0                         0
<TOTAL-REVENUES>                     32,775                     67,422                   100,283
<CGS>                                     0                          0                         0
<TOTAL-COSTS>                           521                      1,055                     1,540
<OTHER-EXPENSES>                          0                          0                         0
<LOSS-PROVISION>                          0                          0                         0
<INTEREST-EXPENSE>                    8,609                     18,659                    26,756
<INCOME-PRETAX>                      18,215                     39,785                    56,242
<INCOME-TAX>                              0                          0                         0
<INCOME-CONTINUING>                  18,215                     39,785                    56,242
<DISCONTINUED>                            0                          0                         0
<EXTRAORDINARY>                           0                          0                         0
<CHANGES>                                 0                          0                         0
<NET-INCOME>                         18,215                     39,785                    56,242
<EPS-PRIMARY>                           .45                        .98                      1.38
<EPS-DILUTED>                           .44                        .97                      1.37
        

</TABLE>