pre_text: annual report 2013 duke realty corporation 37 in addition to the capitalization of overhead costs discussed above , we also capitalized $ 16.8 million , $ 9.4 million and $ 4.3 million of interest costs in the years ended december 31 , 2013 , 2012 and 2011 , respectively . the following table summarizes our second generation capital expenditures by reportable operating segment ( in thousands ) : .
post_text: both our first and second generation expenditures vary significantly between leases on a per square foot basis , dependent upon several factors including the product type , the nature of a tenant's operations , the specific physical characteristics of each individual property as well as the market in which the property is located . second generation expenditures related to the 79 suburban office buildings that were sold in the blackstone office disposition totaled $ 26.2 million in 2011 . dividends and distributions we are required to meet the distribution requirements of the internal revenue code of 1986 , as amended ( the "code" ) , in order to maintain our reit status . we paid dividends of $ 0.68 per common share for each of the years ended december 31 , 2013 , 2012 and 2011 . we expect to continue to distribute at least an amount equal to our taxable earnings , to meet the requirements to maintain our reit status , and additional amounts as determined by our board of directors . distributions are declared at the discretion of our board of directors and are subject to actual cash available for distribution , our financial condition , capital requirements and such other factors as our board of directors deems relevant . at december 31 , 2013 we had three series of preferred stock outstanding . the annual dividend rates on our preferred shares range between 6.5% ( 6.5 % ) and 6.625% ( 6.625 % ) and are paid quarterly in arrears . in february 2013 , we redeemed all of our outstanding series o shares for a total payment of $ 178.0 million , thus reducing our future quarterly dividend commitments by $ 3.7 million . in march 2012 , we redeemed all of our 6.950% ( 6.950 % ) series m cumulative redeemable preferred shares ( "series m shares" ) for a total payment of $ 168.3 million , thus reducing our future quarterly dividend commitments by $ 2.9 million . in july 2011 , we redeemed all of our 7.25% ( 7.25 % ) series n cumulative redeemable preferred shares ( "series n shares" ) for a total payment of $ 108.6 million , thus reducing our future quarterly dividend commitments by $ 2.0 million . debt maturities debt outstanding at december 31 , 2013 had a face value totaling $ 4.3 billion with a weighted average interest rate of 5.49% ( 5.49 % ) and with maturity dates ranging between 2014 and 2028 . of this total amount , we had $ 3.1 billion of unsecured debt , $ 1.1 billion of secured debt and $ 88.0 million outstanding on the drlp unsecured line of credit at december 31 , 2013 . we made scheduled and unscheduled principal payments of $ 1.0 billion on outstanding debt during the year ended december 31 , 2013. .
table: 2013 2012 2011
table: Industrial $41,971 $33,095 $34,872
table: Office 46,600 30,092 63,933
table: Medical Office 3,106 641 410
table: Non-reportable Rental Operations segments 121 56 49
table: Total $91,798 $63,884 $99,264
question: Analyse this data from a financial earnings document. what was the percent of the debt maturities outstanding at december 31 , 2013 that was unsecured debt