SHARE-BASED ARRANGEMENTS

The Company accounts for stock options, restricted stock awards, restricted stock units and performance shares as equity awards and measures the cost of all share-based payments, including stock options, at fair value on the grant date and recognizes this cost in the statement of operations. The Company also has an employee stock purchase plan which is accounted for as a liability award.

Compensation expense for stock options, restricted stock awards and restricted stock units is recognized on a straight-line basis over the vesting period of the awards. Share-based compensation expense recorded for the three-month fiscal periods ended March 29, 2019 and March 30, 2018, was $1.9 million and $1.5 million, respectively.

16. SHARE-BASED ARRANGEMENTS (CONTINUED)

From time-to-time, the Company has issued stock awards with market and performance based conditions. Currently, there is one award with these conditions that has not been settled. The shares for the award granted in 2016 has not yet been determined; however, assuming a 100% achievement level, the number of shares would be 1,060. The Company measures the cost of this award based on its grant date fair value to the extent of the probable number of shares to be earned upon vesting. Amortization of this cost is recorded on a straight-line basis over the requisite service period. Throughout the course of the requisite service period, the Company monitors the level of achievement compared to the target and adjusts the number of shares expected to be earned, and the related compensation expense recorded thereafter, to reflect the updated most probable outcome. Compensation expense for these awards for the three-month fiscal periods ended March 29, 2019, and March 30, 2018, was not material.

Stock option activity was as follows:



	For the Three Months Ended
	March 29, 2019
	Options		Weighted - average exercise price
Options outstanding at beginning of period	935,252		$	45.91
Granted	194,470		$	61.02
Exercised	(29,722	)	$	27.70
Forfeited or expired	(2,913	)	$	61.68
Options outstanding at March 29, 2019	1,097,087		$	49.04

The fair value of each option award is estimated on the date of grant using the Black-Scholes option valuation model. The following table indicates the weighted-average assumptions used in estimating fair value:



	For the Three Months Ended
	March 29, 2019			March 30, 2018
Expected option term (years)	4.9			4.9
Expected volatility	19.4		%	18.1		%
Risk-free interest rate	2.5		%	2.6		%
Expected dividend yield	1.3		%	1.5		%
Per share fair value of options granted		$11.18			$10.65

Restricted stock award and restricted stock unit activity was as follows:



	For the Three Months Ended
	March 29, 2019
	Restricted Stock		Weighted- average grant date fair value
Restricted Stock outstanding at beginning of period	143,697		$	49.97
Granted	44,775		$	61.02
Vested	(45,737	)	$	47.40
Forfeited or expired	(734	)	$	57.46
Restricted Stock outstanding at March 29, 2019	142,001		$	54.25