In April 2014, the Company’s board of directors approved increases to the number of shares authorized for issuance under the 2006 and 2011 Plans by 250,000 and 1,224,021 shares, respectively.

The Company estimated the fair value of employee and non-employee stock options using the Black-Scholes option pricing model. The fair values of employee and non-employee stock options are being amortized on a straight-line basis over the requisite service periods of the respective awards.

The Company believes that the fair value of the stock options issued to non-employees is more reliably measurable than the fair value of the services received. The stock-based compensation expense will fluctuate as the fair market value of the common stock fluctuates. In connection with stock options granted to non-employees, the Company recorded $28,000 and $121,000 of stock-based compensation expense in the three and nine months ended December 31, 2014, respectively. These amounts are included in the stock compensation table below.

The expected term of stock options represents the average period the stock options are expected to remain outstanding and is based on the expected term calculated using the approach prescribed by the Securities and Exchange Commission's Staff Accounting Bulletin No. 110 for “plain vanilla” options. The expected stock price volatility for the Company’s stock options was determined by using an average of the historical share price volatilities of the Company and its industry peers. The Company will continue to analyze the stock price volatility and expected term assumptions as more data for the Company’s common stock and exercise patterns become available. The risk-free interest rate assumption is based on the U.S. Treasury instruments whose term was consistent with the expected term of the Company’s stock options. The expected dividend assumption is based on the Company’s history and expectation of dividend payouts. Compensation expense includes the impact of an estimate for forfeitures for all stock options. The Company estimates forfeitures based on historical experience and reduces compensation expense accordingly. The estimated forfeiture rates used during the three months ended December 31, 2014 ranged from 0.21% to 0.37%.

Stock-based compensation expense is as follows:

At December 31, 2014, there were unrecognized compensation costs of $3,273,000 related to stock options which is expected to be recognized over a weighted-average amortization period of 2.11 years.

No income tax benefit has been recognized relating to stock-based compensation expense and no tax benefits have been realized from exercised stock options.

The Company did not capitalize any cost associated with stock-based compensation.

The fair value of the stock options granted was calculated using the Black-Scholes option-pricing model using the following weighted-average assumptions:

A summary of all option activity as of December 31, 2014 and changes during the nine months then ended is presented below:

The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying stock options and the fair value of the Company’s common stock ($1.43) for stock options.

The Company issues new shares of common stock upon exercise of stock options.