notes to the consolidated financial statements note 1 . general description of business we are a global cruise company . we own royal caribbean international , celebrity cruises , pullmantur , azamara club cruises , cdf croisi e8res de france and a 50% ( 50 % ) joint venture interest in tui cruises . together , these six brands operate a combined 41 ships as of december 31 , 2012 . our ships operate on a selection of worldwide itineraries that call on approximately 455 destinations on all seven continents . basis for preparation of consolidated financial statements the consolidated financial statements are prepared in accordance with accounting principles generally accepted in the united states of america ( 201cgaap 201d ) . estimates are required for the preparation of financial statements in accordance with these principles . actual results could differ from these estimates . all significant intercompany accounts and transactions are eliminated in consolidation . we consolidate entities over which we have control , usually evidenced by a direct ownership interest of greater than 50% ( 50 % ) , and variable interest entities where we are determined to be the primary beneficiary . see note 6 . other assets for further information regarding our variable interest entities . for affiliates we do not control but over which we have significant influence on financial and operat- ing policies , usually evidenced by a direct ownership interest from 20% ( 20 % ) to 50% ( 50 % ) , the investment is accounted for using the equity method . we consolidate the operating results of pullmantur and its wholly-owned subsidiary , cdf croisi e8res de france , on a two-month lag to allow for more timely preparation of our con- solidated financial statements . no material events or transactions affecting pullmantur or cdf croisi e8res de france have occurred during the two-month lag period of november 2012 and december 2012 that would require disclosure or adjustment to our con- solidated financial statements as of december 31 , 2012 , except for the impairment of pullmantur related assets , as described in note 3 . goodwill , note 4 . intangible assets , note 5 . property and equipment and note 12 . income taxes . note 2 . summary of significant accounting policies revenues and expenses deposits received on sales of passenger cruises are initially recorded as customer deposit liabilities on our balance sheet . customer deposits are subsequently recognized as passenger ticket revenues , together with revenues from onboard and other goods and services and all associated direct costs of a voyage , upon completion of voyages with durations of ten days or less , and on a pro-rata basis for voyages in excess of ten days . revenues and expenses include port costs that vary with guest head counts . the amounts of such port costs included in passenger ticket revenues on a gross basis were $ 459.8 million , $ 442.9 million and $ 398.0 million for the years 2012 , 2011 and 2010 , respectively . cash and cash equivalents cash and cash equivalents include cash and market- able securities with original maturities of less than 90 days . inventories inventories consist of provisions , supplies and fuel carried at the lower of cost ( weighted-average ) or market . property and equipment property and equipment are stated at cost less accu- mulated depreciation and amortization . we capitalize interest as part of the cost of acquiring certain assets . improvement costs that we believe add value to our ships are capitalized as additions to the ship and depreciated over the shorter of the improvements 2019 estimated useful lives or that of the associated ship . the estimated cost and accumulated depreciation of replaced or refurbished ship components are written off and any resulting losses are recognized in cruise operating expenses . liquidated damages received from shipyards as a result of the late delivery of a new ship are recorded as reductions to the cost basis of the ship . depreciation of property and equipment is computed using the straight-line method over the estimated useful life of the asset . the useful lives of our ships are generally 30 years , net of a 15% ( 15 % ) projected residual value . the 30-year useful life of our newly constructed ships and 15% ( 15 % ) associated residual value are both based on the weighted-average of all major components of a ship . depreciation for assets under capital leases is computed using the shorter of the lease term or related asset life . ( see note 5 . property and equipment. ) depreciation of property and equipment is computed utilizing the following useful lives: .

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 | years
ships | 30
ship improvements | 3-20
buildings and improvements | 10-40
computer hardware and software | 3-5
transportation equipment and other | 3-30
leasehold improvements | shorter of remaining lease term or useful life 3-30
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computer hardware and software 3 20135 transportation equipment and other 3 201330 leasehold improvements shorter of remaining lease term or useful life 3 201330 0494.indd 71 3/27/13 12:53 pm .

Question: what was the percentage increase in port costs from 2010 to 2012
Program: subtract(459.8, 398.0), divide(#0, 398.0), multiply(#1, const_100)
Answer: 15.52764