Read the following texts and table with financial data from an S&P 500 earnings report carefully.Based on the question-answer history (if provided), answer the last question. The answer may require mathematical calculation based on the data provided.


56 / 57 management 2019s discussion and analysis of financial condition and results of operations junior subordinate deferrable interest debentures in june 2005 , we issued $ 100.0 a0million of trust preferred securities , which are reflected on the balance sheet as junior subordinate deferrable interest debentures . the proceeds were used to repay our revolving credit facility . the $ 100.0 a0million of junior subordi- nate deferrable interest debentures have a 30-year term ending july 2035 . they bear interest at a fixed rate of 5.61% ( 5.61 % ) for the first 10 years ending july 2015 . thereafter , the rate will float at three month libor plus 1.25% ( 1.25 % ) . the securities are redeemable at par . restrictive covenants the terms of the 2011 revolving credit facility and certain of our senior unsecured notes include certain restrictions and covenants which may limit , among other things , our ability to pay dividends ( as discussed below ) , make certain types of investments , incur additional indebtedness , incur liens and enter into negative pledge agreements and the disposition of assets , and which require compliance with financial ratios including our minimum tangible net worth , a maximum ratio of total indebtedness to total asset value , a minimum ratio of ebitda to fixed charges and a maximum ratio of unsecured indebtedness to unencumbered asset value . the dividend restriction referred to above provides that we will not during any time when we are in default , make distributions with respect to common stock or other equity interests , except to enable us to continue to qualify as a reit for federal income tax purposes . as of december a031 , 2011 and 2010 , we were in compli- ance with all such covenants . market rate risk we are exposed to changes in interest rates primarily from our floating rate borrowing arrangements . we use interest rate deriv- ative instruments to manage exposure to interest rate changes . a a0hypothetical 100 a0basis point increase in interest rates along the entire interest rate curve for 2011 and 2010 , would increase our annual interest cost by approximately $ 12.3 a0million and $ 11.0 a0mil- lion and would increase our share of joint venture annual interest cost by approximately $ 4.8 a0million and $ 6.7 a0million , respectively . we recognize all derivatives on the balance sheet at fair value . derivatives that are not hedges must be adjusted to fair value through income . if a derivative is a hedge , depending on the nature of the hedge , changes in the fair value of the derivative will either be offset against the change in fair value of the hedged asset , liability , or firm commitment through earnings , or recognized in other comprehensive income until the hedged item is recognized in earnings . the ineffective portion of a derivative 2019s change in fair value is recognized immediately in earnings . approximately $ 4.8 a0billion of our long- term debt bore interest a0at fixed rates , and therefore the fair value of these instru- ments is affected by changes in the market interest rates . the interest rate on our variable rate debt and joint venture debt as of december a031 , 2011 ranged from libor plus 150 a0basis points to libor plus 350 a0basis points . contractual obligations combined aggregate principal maturities of mortgages and other loans payable , our 2011 revolving credit facility , senior unsecured notes ( net of discount ) , trust preferred securities , our share of joint venture debt , including as- of-right extension options , estimated interest expense ( based on weighted average interest rates for the quarter ) , and our obligations under our capital lease and ground leases , as of december a031 , 2011 are as follows ( in thousands ) : . <table class='wikitable'><tr><td>1</td><td>-</td><td>2012</td><td>2013</td><td>2014</td><td>2015</td><td>2016</td><td>thereafter</td><td>total</td></tr><tr><td>2</td><td>property mortgages</td><td>$ 52443</td><td>$ 568649</td><td>$ 647776</td><td>$ 270382</td><td>$ 556400</td><td>$ 2278190</td><td>$ 4373840</td></tr><tr><td>3</td><td>revolving credit facility</td><td>2014</td><td>2014</td><td>2014</td><td>2014</td><td>350000</td><td>2014</td><td>350000</td></tr><tr><td>4</td><td>trust preferred securities</td><td>2014</td><td>2014</td><td>2014</td><td>2014</td><td>2014</td><td>100000</td><td>100000</td></tr><tr><td>5</td><td>senior unsecured notes</td><td>119423</td><td>2014</td><td>98578</td><td>657</td><td>274804</td><td>777194</td><td>1270656</td></tr><tr><td>6</td><td>capital lease</td><td>1555</td><td>1555</td><td>1555</td><td>1592</td><td>1707</td><td>42351</td><td>50315</td></tr><tr><td>7</td><td>ground leases</td><td>33429</td><td>33429</td><td>33429</td><td>33429</td><td>33533</td><td>615450</td><td>782699</td></tr><tr><td>8</td><td>estimated interest expense</td><td>312672</td><td>309280</td><td>269286</td><td>244709</td><td>212328</td><td>470359</td><td>1818634</td></tr><tr><td>9</td><td>joint venture debt</td><td>176457</td><td>93683</td><td>123983</td><td>102476</td><td>527814</td><td>800102</td><td>1824515</td></tr><tr><td>10</td><td>total</td><td>$ 695979</td><td>$ 1006596</td><td>$ 1174607</td><td>$ 653245</td><td>$ 1956586</td><td>$ 5083646</td><td>$ 10570659</td></tr></table> .
Question: what is the sum of the joint venture income costs increased over 2010 and 2011?

23.3