We have various stock-based compensation programs under which awards, including stock options, restricted stock, restricted stock units, and performance awards, may be granted to employees and non-employee directors. These programs and related accounting are described in Note 11 to the Consolidated Financial Statements included in our Annual Report on Form 10-K for the fiscal year ended May 31, 2015.

Compensation expense related to stock-based payments recognized in the Consolidated Statements of Earnings was as follows:

		Quarter Ended				Six-Month Period Ended
In Millions		Nov. 29, 2015		Nov. 23, 2014		Nov. 29, 2015		Nov. 23, 2014
Compensation expense related to stock-based payments	$	21.4	$	22.1	$	54.3	$	67.7

Compensation expense related to stock-based payments recognized in the Consolidated Statements of Earnings includes amounts recognized in restructuring, impairment, and other exit costs.

As of November 29, 2015, unrecognized compensation expense related to non-vested stock options, restricted stock units, and performance award units was $118.0 million. This expense will be recognized over 22 months, on average.

Net cash proceeds from the exercise of stock options less shares used for withholding taxes and the intrinsic value of options exercised were as follows:

		Six-Month Period Ended
In Millions		Nov. 29, 2015		Nov. 23, 2014
Net cash proceeds	$	64.5	$	35.9
Intrinsic value of options exercised	$	102.0	$	40.1

We estimate the fair value of each stock option on the grant date using a Black-Scholes option-pricing model. Black-Scholes option-pricing models require us to make predictive assumptions regarding future stock price volatility, employee exercise behavior, and dividend yield. We estimate our future stock price volatility using the historical volatility over the expected term of the option, excluding time periods of volatility we believe a marketplace participant would exclude in estimating our stock price volatility. We also have considered, but did not use, implied volatility in our estimate, because trading activity in options on our stock, especially those with tenors of greater than 6 months, is insufficient to provide a reliable measure of expected volatility. Our method of selecting the other valuation assumptions is explained in Note 11 to the Consolidated Financial Statements included in our Annual Report on Form 10-K for the fiscal year ended May 31, 2015.

The estimated fair values of stock options granted and the assumptions used for the Black-Scholes option-pricing model were as follows:


	Six-Month Period Ended
	Nov. 29, 2015		Nov. 23, 2014
Estimated fair values of stock options granted	$ 7.24		$ 7.22
Assumptions:
Risk-free interest rate	2.4	%	2.6	%
Expected term	8.5 years		8.5 years
Expected volatility	17.6	%	17.5	%
Dividend yield	3.2	%	3.0	%

	Options Outstanding (Thousands)		Weighted-Average Exercise Price Per Share	Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (Millions)
Balance as of May 31, 2015	39,077.2	$	34.35
Granted	1,930.2		55.72
Exercised	(3,412.4)		28.15
Forfeited or expired	(53.8)		46.78
Outstanding as of Nov. 29, 2015	37,541.2	$	35.99	4.42	$	841.6
Exercisable as of Nov. 29, 2015	27,385.2	$	31.68	3.18	$	732.1

	Equity Classified			Liability Classified
	Share-Settled Units (Thousands)		Weighted-Average Grant-Date Fair Value	Share-Settled Units (Thousands)		Weighted-Average Grant-Date Fair Value
Non-vested as of May 31, 2015	6,235.6	$	46.44	237.0	$	44.84
Granted	1,253.7		55.88	63.4		55.83
Vested	(1,923.9)		47.18	(68.5)		40.49
Forfeited	(161.2)		48.24	(15.6)		51.76
Non-vested as of Nov. 29, 2015	5,404.2	$	48.32	216.3	$	48.39

The total grant-date fair value of restricted stock unit awards that vested in the six-month period ended November 29, 2015 was $93.7 million, and restricted stock units with a grant-date fair value of $99.0 million vested in the six-month period ended November 23, 2014.