Equity Incentive Plan
On May 17, 2019, the Company’s stockholders approved the 2019 Omnibus Equity Incentive Plan (the “2019 Plan”). Concurrently, the 2011 Omnibus Equity Incentive Plan (the “2011 Plan”) was terminated and any shares remaining available for new grants under the 2011 Plan share reserve were extinguished. The purpose of the 2019 Plan is to promote the interests of the Company and its stockholders by (i) attracting and retaining key officers, employees and directors of, and consultants to, the Company and its Subsidiaries and Affiliates; (ii) motivating such individuals by means of performance-related incentives to achieve long-range performance goals; (iii) enabling such individuals to participate in the long-term growth and financial success of the Company; (iv) encouraging ownership of stock in the Company by such individuals; and (v) linking their compensation to the long-term interests of the Company and its stockholders.
The 2019 Plan is administered by the Compensation and Human Capital Committee (the “Committee”) of the Board of Directors and allows for the issuance of stock options, stock appreciation rights (“SARs”), RSAs, restricted share units, performance awards, or other stock-based awards. Stock option exercise prices are fixed by the Committee but shall not be less than the fair market value of a common share on the date of the grant of the option, except in the case of substitute awards. Similarly, the grant price of an SAR may not be less than the fair market value of a common share on the date of the grant. The Committee will determine the expiration date of each stock option and SAR, but in no case shall the stock option or SAR be exercisable after the expiration of 10 years from the date of the grant. The 2019 Plan provides for 2,600,000 shares available for grant. As of December 27, 2019, there were 2,222,088 shares available for grant.
Stock compensation expense was $4,399, $4,094 and $3,018 for the fiscal years ended December 27, 2019, December 28, 2018 and December 29, 2017, respectively. The related tax benefit for stock-based compensation was $883, $864 and $1,283 for the fiscal years ended December 27, 2019, December 28, 2018 and December 29, 2017, respectively.
The following table reflects the activity of RSAs during the fiscal years ended December 27, 2019 and December 28, 2018:
The fair value of RSAs vested during the fiscal years ended December 27, 2019, December 28, 2018 and December 29, 2017, was $3,742, $2,936 and $1,703, respectively.
These awards are a mix of time-, market- and performance-based grants awarded to key employees and non-employee directors which vest over a range of periods of up to five-years. The market- and performance-based RSAs cliff vest, if at all, after the conclusion of a three-year performance period and vesting is subject to the award recipient’s continued service to the Company as of the vesting date. The number of performance-based RSAs that ultimately vest is based on the Company’s attainment of certain profitability and return on invested capital targets.
During fiscal 2019, the Company awarded market-based RSAs that vest based on the Company’s attainment of an average closing trade price of the Company’s common stock of $39.86 per share, based on an average of 20 consecutive trading days. The grant date fair value of these market-based performance awards was determined using a Monte Carlo simulation in order to simulate a range of possible future stock prices. Key assumptions used included a risk-free interest rate of 2.2% and expected volatility of 44.6%.
Table:
 | Shares  | Weighted Average Grant Date Fair Value
Unvested at December 29, 2017 | 329,761 | $16.69
Granted  | 311,957 | 23.62
Vested  | (113,482) | 17.60
Forfeited  | (1,506) | 17.13
Unvested at December 28, 2018 | 526,730 | $20.60
Granted  | 384,531 | 34.44
Vested  | (115,459) | 21.32
Forfeited  | (55,193) | 20.46
Unvested at December 27, 2019  | 740,609 | $27.68


Question: What is the change in the number of unvested shares between December 29, 2017 and December 28, 2018?
Answer: 196969
Calculation: 526,730-329,761