EXHIBIT 99.1
   SELECTED QUARTERLY FINANCIAL INFORMATION
           (UNAUDITED)
   
   Selected  quarterly  information for the years ended December  31,  1998  and
   1997 is as follows (in thousands, except per share amounts):
   <TABLE>
   <CAPTION>
   
                                                 Quarter Ended
                         -------------------------------------------------------
   1998                  December 31   September 30   June 30       March 31
   ---------------       -----------   ------------   ----------    ----------
   <S>                   <C>           <C>            <C>           <C>
   Revenues from
    Rental Operations    $ 95,522      $ 90,348       $ 83,079      $ 79,676
   Revenues from
    Service Operations      5,510         7,284          7,022         4,900
   Net income available 
    for common shares      23,302        23,449         21,858        22,262
   Basic income per
    common share (2)     $   0.28      $   0.29       $   0.27      $   0.29
   Diluted income per
    common share (2)     $   0.27      $   0.29       $   0.27      $   0.29
   Weighted average
    common shares (2)      84,394        81,594         80,080        76,655
   Weighted average
    common and dilutive
    potential common
    shares (2)             96,074        93,279         91,830        88,596
   Funds From
    Operations (1)        $42,990       $39,421        $36,933       $34,730
   Cash flow provided
    by (used by):
    Operating
     activities           $72,079       $48,798        $61,260       $39,051
    Investing
     activities          (233,013)     (119,313)      (242,439)     (109,049)
    Financing
     activities           145,851        70,169        174,389        88,814
   
   1997
   ---------------------------
   Revenues from
    Rental Operations    $ 70,980      $ 56,218       $ 51,586      $ 50,918
   Revenues from
    Service Operations   $  7,393      $  5,917       $  5,129      $  3,939
   Net income available
    for common shares    $ 19,406      $ 16,911       $ 14,696      $ 14,986
   Basic income
    per common share (2) $  0. 26      $   0.26       $  0. 23      $   0.24
   Diluted income
    per common share (2) $  0. 25      $   0.26       $  0. 23      $   0.24
   Weighted average
    common shares (2)      75,466        65,309         63,168        61,624
   Weighted average
    common and dilutive
    potential common
    shares (2)             86,649        72,971         70,576        69,579
   Funds From
    Operations (1)       $ 33,126      $ 26,007       $ 24,406      $ 23,717
   Cash flow
     provided by (used by):
    Operating
     activities          $ 49,057      $ 38,676       $ 42,489      $ 28,973
    Investing
     activities          (216,788)     (205,129)      (134,244)      (41,163)
    Financing
     activities             3,952       337,478         81,865        19,853
   </TABLE>
   
   
   
(1)  Funds From Operations is defined by the National Association of Real Estate
     Investment Trusts as net income or loss excluding gains or losses from debt
     restructuring and sales of property plus depreciation and amortization, and
     after adjustments for minority interest and unconsolidated companies
     (adjustments for minority interest and unconsolidated companies are
     calculated to reflect Funds From Operations on same basis). Funds From
     Operations does not represent cash flow from operations as defined by
     generally accepted accounting principles, should not be considered as
     an alternative to net income as an indicator of the Company's operating
     performance, and is not indicative of cash available to fund all cash
     flow needs.

(2)  Amounts adjusted to reflect the General Partner's two-for-one stock split
     effected in August 1997.