Accumulated
                                                                                      Additional                 Other
                                                General     Limited         Common     Paid in   Accumulated Comprehensive
                                                Partner     Partners        Stock      Capital    Deficit        Income     Total
                                                -------     --------        -----      -------    -------        ------     -----
Balance at January 1, 1997                    $  (2,314)   $(175,523)                                                     $(177,837)
   Net income                                       739       73,143                                                         73,882
   Purchase of limited partner's
     interest                                        --      (10,250)                                                       (10,250)
   Purchase of warrants                              --          366                                                             366
   Accretion of preferred limited units            (153)     (15,122)                                                       (15,275)
   Depreciation of warrants                          --        1,132                                                          1,132
                                            ---------------------------------------------------------------------------------------
Balance at December 31, 1997                     (1,728)    (126,254)                                                      (127,982)

   Net income                                     1,386      137,220                                                        138,606

   Accretion of redeemable Class B units            (57)      (5,672)                                                        (5,729)
   Purchase of limited partner's units             (165)     (16,321)                                                       (16,486)

   Warrants exercised                                24        2,363                                                          2,387
   Warrants expired                                   9          900                                                            909
   Purchase of warrants                               4          363                                                            367
                                            ---------------------------------------------------------------------------------------
Balance at December 31, 1998                       (527)      (7,401)                                                        (7,928)


   Net loss                                        (120)     (11,900)                             $ (72,188)                (84,208)

   Unrealized gain on marketable
     securities                                                                                                $   3,168      3,168
                                                                                                                        ------------
   Total comprehensive loss                                                                                                 (81,040)
                                                                                                                        ------------
   Accretion of redeemable Class B units            (71)      (7,047)                                                        (7,118)

   Recapitalization                                 718       26,348    $     219    $ (27,285)                                  --
   Issuance of common stock in exchange
     for redeemable units                                                     110       58,327                               58,437
   Compensation associated with
     issuance of common stock to
     employees                                                                          18,715                               18,715
   Issuance of common stock in initial
     public offering                                                          265      606,729                              606,994
                                            ---------------------------------------------------------------------------------------
Balance at December 31, 1999                  $      --    $      --    $     594    $ 656,486    $ (72,188)   $   3,168  $ 588,060
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