15 . leases in january 1996 , the company entered into a lease agreement with an unrelated third party for a new corporate office facility , which the company occupied in february 1997 . in may 2004 , the company entered into the first amendment to this lease agreement , effective january 1 , 2004 . the lease was extended from an original period of 10 years , with an option for five additional years , to a period of 18 years from the inception date , with an option for five additional years . the company incurred lease rental expense related to this facility of $ 1.3 million in 2008 , 2007 and 2006 . the future minimum lease payments are $ 1.4 million per annum from january 1 , 2009 to december 31 , 2014 . the future minimum lease payments from january 1 , 2015 through december 31 , 2019 will be determined based on prevailing market rental rates at the time of the extension , if elected . the amended lease also provided for the lessor to reimburse the company for up to $ 550000 in building refurbishments completed through march 31 , 2006 . these amounts have been recorded as a reduction of lease expense over the remaining term of the lease . the company has also entered into various noncancellable operating leases for equipment and office space . office space lease expense totaled $ 9.3 million , $ 6.3 million and $ 4.7 million for the years ended december 31 , 2008 , 2007 and 2006 , respectively . future minimum lease payments under noncancellable operating leases for office space in effect at december 31 , 2008 are $ 8.8 million in 2009 , $ 6.6 million in 2010 , $ 3.0 million in 2011 , $ 1.8 million in 2012 and $ 1.1 million in 2013 . 16 . royalty agreements the company has entered into various renewable , nonexclusive license agreements under which the company has been granted access to the licensor 2019s technology and the right to sell the technology in the company 2019s product line . royalties are payable to developers of the software at various rates and amounts , which generally are based upon unit sales or revenue . royalty fees are reported in cost of goods sold and were $ 6.3 million , $ 5.2 million and $ 3.9 million for the years ended december 31 , 2008 , 2007 and 2006 , respectively . 17 . geographic information revenue to external customers is attributed to individual countries based upon the location of the customer . revenue by geographic area is as follows: .

year ended december 31 , 2008: united states: 151688
germany: 68390
japan: 66960
canada: 8033
other european: 127246
other international: 56022
total revenue: 478339
year ended december 31 , 2007: united states: 131777
germany: 50973
japan: 50896
canada: 4809
other european: 108971
other international: 37914
total revenue: 385340
year ended december 31 , 2006: united states: 94282
germany: 34567
japan: 35391
canada: 4255
other european: 70184
other international: 24961
total revenue: 263640

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Questions:
what is the total future minimum lease payments under noncancellable operating leases for office space for 2009 and 2010?
what about if 2011 is added?
and if 2012 is added?
what about if 2013 is added
what is the average for these four years?
what is the revenue generated in united states in 2008?
what about the total revenue in 2008?
what portion of revenue is generated in united states?

Answers:
15.4
18.4
20.2
21.3
5.325
151688
478339
31.7%