mastercard incorporated notes to consolidated financial statements 2014continued in september 2010 , the company 2019s board of directors authorized a plan for the company to repurchase up to $ 1 billion of its class a common stock in open market transactions .the company did not repurchase any shares under this plan during 2010 .as of february 16 , 2011 , the company had completed the repurchase of approximately 0.3 million shares of its class a common stock at a cost of approximately $ 75 million .note 18 .share based payment and other benefits in may 2006 , the company implemented the mastercard incorporated 2006 long-term incentive plan , which was amended and restated as of october 13 , 2008 ( the 201cltip 201d ) .the ltip is a shareholder-approved omnibus plan that permits the grant of various types of equity awards to employees .the company has granted restricted stock units ( 201crsus 201d ) , non-qualified stock options ( 201coptions 201d ) and performance stock units ( 201cpsus 201d ) under the ltip .the rsus generally vest after three to four years .the options , which expire ten years from the date of grant , generally vest ratably over four years from the date of grant .the psus generally vest after three years .additionally , the company made a one-time grant to all non-executive management employees upon the ipo for a total of approximately 440 thousand rsus ( the 201cfounders 2019 grant 201d ) .the founders 2019 grant rsus vested three years from the date of grant .the company uses the straight-line method of attribution for expensing equity awards .compensation expense is recorded net of estimated forfeitures .estimates are adjusted as appropriate .upon termination of employment , excluding retirement , all of a participant 2019s unvested awards are forfeited .however , when a participant terminates employment due to retirement , the participant generally retains all of their awards without providing additional service to the company .eligible retirement is dependent upon age and years of service , as follows : age 55 with ten years of service , age 60 with five years of service and age 65 with two years of service .compensation expense is recognized over the shorter of the vesting periods stated in the ltip , or the date the individual becomes eligible to retire .there are 11550000 shares of class a common stock reserved for equity awards under the ltip .although the ltip permits the issuance of shares of class b common stock , no such shares have been reserved for issuance .shares issued as a result of option exercises and the conversions of rsus and psus are expected to be funded primarily with the issuance of new shares of class a common stock .stock options the fair value of each option is estimated on the date of grant using a black-scholes option pricing model .the following table presents the weighted-average assumptions used in the valuation and the resulting weighted- average fair value per option granted for the years ended december 31: .
[['', '2010', '2009', '2008'], ['risk-free rate of return', '2.7% ( 2.7 % )', '2.5% ( 2.5 % )', '3.2% ( 3.2 % )'], ['expected term ( in years )', '6.25', '6.17', '6.25'], ['expected volatility', '32.7% ( 32.7 % )', '41.7% ( 41.7 % )', '37.9% ( 37.9 % )'], ['expected dividend yield', '0.3% ( 0.3 % )', '0.4% ( 0.4 % )', '0.3% ( 0.3 % )'], ['weighted-average fair value per option granted', '$ 84.62', '$ 71.03', '$ 78.54']]
the risk-free rate of return was based on the u.s .treasury yield curve in effect on the date of grant .the company utilizes the simplified method for calculating the expected term of the option based on the vesting terms and the contractual life of the option .the expected volatility for options granted during 2010 and 2009 was based on the average of the implied volatility of mastercard and a blend of the historical volatility of mastercard and the historical volatility of a group of companies that management believes is generally comparable to .

Question: what was the percentage change in the risk-free rate of return from 2009 to 2010
Answer: 8%
Explanation: the risk-free rate of return increased by 8% from 2009 to 2010