table of contents the company uses some custom components that are not commonly used by its competitors , and new products introduced by the company often utilize custom components available from only one source . when a component or product uses new technologies , initial capacity constraints may exist until the suppliers 2019 yields have matured or manufacturing capacity has increased . if the company 2019s supply of components for a new or existing product were delayed or constrained , or if an outsourcing partner delayed shipments of completed products to the company , the company 2019s financial condition and operating results could be materially adversely affected . the company 2019s business and financial performance could also be materially adversely affected depending on the time required to obtain sufficient quantities from the original source , or to identify and obtain sufficient quantities from an alternative source . continued availability of these components at acceptable prices , or at all , may be affected if those suppliers concentrated on the production of common components instead of components customized to meet the company 2019s requirements . the company has entered into agreements for the supply of many components ; however , there can be no guarantee that the company will be able to extend or renew these agreements on similar terms , or at all . therefore , the company remains subject to significant risks of supply shortages and price increases that could materially adversely affect its financial condition and operating results . substantially all of the company 2019s hardware products are manufactured by outsourcing partners that are located primarily in asia . a significant concentration of this manufacturing is currently performed by a small number of outsourcing partners , often in single locations . certain of these outsourcing partners are the sole- sourced suppliers of components and manufacturers for many of the company 2019s products . although the company works closely with its outsourcing partners on manufacturing schedules , the company 2019s operating results could be adversely affected if its outsourcing partners were unable to meet their production commitments . the company 2019s purchase commitments typically cover its requirements for periods up to 150 days . other off-balance sheet commitments operating leases the company leases various equipment and facilities , including retail space , under noncancelable operating lease arrangements . the company does not currently utilize any other off-balance sheet financing arrangements . the major facility leases are typically for terms not exceeding 10 years and generally contain multi-year renewal options . as of september 26 , 2015 , the company had a total of 463 retail stores . leases for retail space are for terms ranging from five to 20 years , the majority of which are for 10 years , and often contain multi-year renewal options . as of september 26 , 2015 , the company 2019s total future minimum lease payments under noncancelable operating leases were $ 6.3 billion , of which $ 3.6 billion related to leases for retail space . rent expense under all operating leases , including both cancelable and noncancelable leases , was $ 794 million , $ 717 million and $ 645 million in 2015 , 2014 and 2013 , respectively . future minimum lease payments under noncancelable operating leases having remaining terms in excess of one year as of september 26 , 2015 , are as follows ( in millions ) : .

$ 772: 2017: 774
2018: 744
2019: 715
2020: 674
thereafter: 2592
total: 6271

other commitments the company utilizes several outsourcing partners to manufacture sub-assemblies for the company 2019s products and to perform final assembly and testing of finished products . these outsourcing partners acquire components and build product based on demand information supplied by the company , which typically covers periods up to 150 days . the company also obtains individual components for its products from a wide variety of individual suppliers . consistent with industry practice , the company acquires components through a combination of purchase orders , supplier contracts and open orders based on projected demand information . where appropriate , the purchases are applied to inventory component prepayments that are outstanding with the respective supplier . as of september 26 , 2015 , the company had outstanding off-balance sheet third-party manufacturing commitments and component purchase commitments of $ 29.5 billion . apple inc . | 2015 form 10-k | 65 .

Questions:
what was the sum of rent expense under all operating leases in 2015 and 2014?
what was the rent expense in 2013?
what is the total rent expense for the 3 years?

Answers:
1511
645
2156