adobe systems incorporated notes to consolidated financial statements ( continued ) foreign currency translation we translate assets and liabilities of foreign subsidiaries , whose functional currency is their local currency , at exchange rates in effect at the balance sheet date . we translate revenue and expenses at the monthly average exchange rates . we include accumulated net translation adjustments in stockholders 2019 equity as a component of accumulated other comprehensive income . property and equipment we record property and equipment at cost less accumulated depreciation and amortization . property and equipment are depreciated using the straight-line method over their estimated useful lives ranging from 1 to 5 years for computers and equipment , 1 to 6 years for furniture and fixtures and up to 35 years for buildings . leasehold improvements are amortized using the straight-line method over the lesser of the remaining respective lease term or useful lives . goodwill , purchased intangibles and other long-lived assets we review our goodwill for impairment annually , or more frequently , if facts and circumstances warrant a review . we completed our annual impairment test in the second quarter of fiscal 2009 and determined that there was no impairment . goodwill is assigned to one or more reporting segments on the date of acquisition . we evaluate goodwill for impairment by comparing the fair value of each of our reporting segments to its carrying value , including the associated goodwill . to determine the fair values , we use the market approach based on comparable publicly traded companies in similar lines of businesses and the income approach based on estimated discounted future cash flows . our cash flow assumptions consider historical and forecasted revenue , operating costs and other relevant factors . we amortize intangible assets with finite lives over their estimated useful lives and review them for impairment whenever an impairment indicator exists . we continually monitor events and changes in circumstances that could indicate carrying amounts of our long-lived assets , including our intangible assets may not be recoverable . when such events or changes in circumstances occur , we assess recoverability by determining whether the carrying value of such assets will be recovered through the undiscounted expected future cash flows . if the future undiscounted cash flows are less than the carrying amount of these assets , we recognize an impairment loss based on the excess of the carrying amount over the fair value of the assets . we did not recognize any intangible asset impairment charges in fiscal 2009 , 2008 or 2007 . our intangible assets are amortized over their estimated useful lives of 1 to 13 years as shown in the table below . amortization is based on the pattern in which the economic benefits of the intangible asset will be consumed . weighted average useful life ( years ) .

weighted average useful life ( years ): purchased technology: 7
localization: 1
trademarks: 7
customer contracts and relationships: 10
other intangibles: 2

software development costs capitalization of software development costs for software to be sold , leased , or otherwise marketed begins upon the establishment of technological feasibility , which is generally the completion of a working prototype that has been certified as having no critical bugs and is a release candidate . amortization begins once the software is ready for its intended use , generally based on the pattern in which the economic benefits will be consumed . to date , software development costs incurred between completion of a working prototype and general availability of the related product have not been material . revenue recognition our revenue is derived from the licensing of software products , consulting , hosting services and maintenance and support . primarily , we recognize revenue when persuasive evidence of an arrangement exists , we have delivered the product or performed the service , the fee is fixed or determinable and collection is probable. .

Questions:
what is the sum of the number of years of trademarks and customer contracts and relationships?
what is that sum divided by 2?

Answers:
17.0
8.5