Financial report context:
39 annual report 2010 duke realty corporation | | related party transactions we provide property and asset management , leasing , construction and other tenant related services to unconsolidated companies in which we have equity interests . for the years ended december 31 , 2010 , 2009 and 2008 , respectively , we earned management fees of $ 7.6 million , $ 8.4 million and $ 7.8 million , leasing fees of $ 2.7 million , $ 4.2 million and $ 2.8 million and construction and development fees of $ 10.3 million , $ 10.2 million and $ 12.7 million from these companies . we recorded these fees based on contractual terms that approximate market rates for these types of services , and we have eliminated our ownership percentages of these fees in the consolidated financial statements . commitments and contingencies we have guaranteed the repayment of $ 95.4 million of economic development bonds issued by various municipalities in connection with certain commercial developments . we will be required to make payments under our guarantees to the extent that incremental taxes from specified developments are not sufficient to pay the bond debt service . management does not believe that it is probable that we will be required to make any significant payments in satisfaction of these guarantees . we also have guaranteed the repayment of secured and unsecured loans of six of our unconsolidated subsidiaries . at december 31 , 2010 , the maximum guarantee exposure for these loans was approximately $ 245.4 million . with the exception of the guarantee of the debt of 3630 peachtree joint venture , for which we recorded a contingent liability in 2009 of $ 36.3 million , management believes it probable that we will not be required to satisfy these guarantees . we lease certain land positions with terms extending to december 2080 , with a total obligation of $ 103.6 million . no payments on these ground leases are material in any individual year . we are subject to various legal proceedings and claims that arise in the ordinary course of business . in the opinion of management , the amount of any ultimate liability with respect to these actions will not materially affect our consolidated financial statements or results of operations . contractual obligations at december 31 , 2010 , we were subject to certain contractual payment obligations as described in the table below: .

Financial table:
contractual obligations: long-term debt ( 1 ); payments due by period ( in thousands ) total: $ 5413606; payments due by period ( in thousands ) 2011: $ 629781; payments due by period ( in thousands ) 2012: $ 548966; payments due by period ( in thousands ) 2013: $ 725060; payments due by period ( in thousands ) 2014: $ 498912; payments due by period ( in thousands ) 2015: $ 473417; payments due by period ( in thousands ) thereafter: $ 2537470
contractual obligations: lines of credit ( 2 ); payments due by period ( in thousands ) total: 214225; payments due by period ( in thousands ) 2011: 28046; payments due by period ( in thousands ) 2012: 9604; payments due by period ( in thousands ) 2013: 176575; payments due by period ( in thousands ) 2014: -; payments due by period ( in thousands ) 2015: -; payments due by period ( in thousands ) thereafter: -
contractual obligations: share of debt of unconsolidated joint ventures ( 3 ); payments due by period ( in thousands ) total: 447573; payments due by period ( in thousands ) 2011: 87602; payments due by period ( in thousands ) 2012: 27169; payments due by period ( in thousands ) 2013: 93663; payments due by period ( in thousands ) 2014: 34854; payments due by period ( in thousands ) 2015: 65847; payments due by period ( in thousands ) thereafter: 138438
contractual obligations: ground leases; payments due by period ( in thousands ) total: 103563; payments due by period ( in thousands ) 2011: 2199; payments due by period ( in thousands ) 2012: 2198; payments due by period ( in thousands ) 2013: 2169; payments due by period ( in thousands ) 2014: 2192; payments due by period ( in thousands ) 2015: 2202; payments due by period ( in thousands ) thereafter: 92603
contractual obligations: operating leases; payments due by period ( in thousands ) total: 2704; payments due by period ( in thousands ) 2011: 840; payments due by period ( in thousands ) 2012: 419; payments due by period ( in thousands ) 2013: 395; payments due by period ( in thousands ) 2014: 380; payments due by period ( in thousands ) 2015: 370; payments due by period ( in thousands ) thereafter: 300
contractual obligations: development and construction backlog costs ( 4 ); payments due by period ( in thousands ) total: 521041; payments due by period ( in thousands ) 2011: 476314; payments due by period ( in thousands ) 2012: 44727; payments due by period ( in thousands ) 2013: -; payments due by period ( in thousands ) 2014: -; payments due by period ( in thousands ) 2015: -; payments due by period ( in thousands ) thereafter: -
contractual obligations: other; payments due by period ( in thousands ) total: 1967; payments due by period ( in thousands ) 2011: 1015; payments due by period ( in thousands ) 2012: 398; payments due by period ( in thousands ) 2013: 229; payments due by period ( in thousands ) 2014: 90; payments due by period ( in thousands ) 2015: 54; payments due by period ( in thousands ) thereafter: 181
contractual obligations: total contractual obligations; payments due by period ( in thousands ) total: $ 6704679; payments due by period ( in thousands ) 2011: $ 1225797; payments due by period ( in thousands ) 2012: $ 633481; payments due by period ( in thousands ) 2013: $ 998091; payments due by period ( in thousands ) 2014: $ 536428; payments due by period ( in thousands ) 2015: $ 541890; payments due by period ( in thousands ) thereafter: $ 2768992

Additional report context:
( 1 ) our long-term debt consists of both secured and unsecured debt and includes both principal and interest . interest expense for variable rate debt was calculated using the interest rates as of december 31 , 2010 . ( 2 ) our unsecured lines of credit consist of an operating line of credit that matures february 2013 and the line of credit of a consolidated subsidiary that matures july 2011 . interest expense for our unsecured lines of credit was calculated using the most recent stated interest rates that were in effect . ( 3 ) our share of unconsolidated joint venture debt includes both principal and interest . interest expense for variable rate debt was calculated using the interest rate at december 31 , 2010 . ( 4 ) represents estimated remaining costs on the completion of owned development projects and third-party construction projects. .

Question: what is the total long-term debt as a percentage of total contractual obligations?
Answer: 80.7%