NOTE 11 – SHAREBASED COMPENSATION Total sharebased compensation expense recorded for employee equity awards issued pursuant to the Option and Incentive Plan and for shares issued under the ESPP was $10.0 million, $7.3 million and $7.8 million for the fiscal years ended June 30, 2017, 2016 and 2015, respectively. Sharebased compensation for the year ended June 30, 2017, 2016 and 2015 consisted of:
                Year Ended June 30,    2017   2016   2015  Awards issued to employees   $  9,965 
  $  7,283 
  $  7,513 
 Options issued to transitioned CMC employees, net of other CMC sharebased compensation amounts   — 
  — 
  251 
 Other nonemployee awards   — 
  — 
  296 
 Total sharebased compensation expense   $  9,965 
  $  7,283 
  $  8,060 

We use the BlackScholes option pricing model to estimate the fair value of our sharebased awards. In applying this model, we use the following assumptions:
  •  Riskfree interest rate  We determine the riskfree interest rate by using a weighted average assumption equivalent to the expected term based on the U.S. Treasury constant maturity rate. 
  •  Expected term  We estimate the expected term of our options based upon historical exercises and postvesting termination behavior. 
  •  Expected volatility  We estimate expected volatility using daily historical trading data of our common stock. 
  •  Dividend yield  We have never paid dividends and currently have no plans to do so; therefore, no dividend yield is applied. 
Option Awards
The fair values of our employee option awards were estimated using the assumptions below, which yielded the following weighted average grant date fair values for the periods presented:
        Year Ended June 30,   2017   2016   2015        Riskfree interest rate  1.1%  2.1%   1.3%  1.8%   1.5%  2.1%  Expected option term in years  4.0  5.5   5.5  6.25   6.25  Expected volatility  57.0%  66.8%   55.7%  60.1%   60.8%  67.1%  Dividend yield  0%   0%   0%  Weighted average grant date fair value  $4.46   $1.95   $3.86 
