Stock-Based Compensation: (Tables)

9 Months Ended

Feb. 29, 2012

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan

The following table summarizes the Company’s total stock-based compensation expense:

	Three Months Ended February 29 and 28,				Nine Months Ended February 29 and 28,
	2012		2011		2012		2011
	(in millions)
Stock Options (1)	$	26	$	21	$	70	$	56
ESPPs		4		3		12		11
Restricted Stock		4		4		13		11
Total stock-based compensation expense	$	34	$	28	$	95	$	78

(1) Expense for stock options includes the expense associated with stock appreciation rights. Accelerated stock option expense is recorded for employees eligible for accelerated stock option vesting upon retirement. Accelerated stock option expense for the three and nine month periods ended February 29, 2012 was $4 million and $12 million, respectively. The accelerated stock option expense for the three and nine month periods ended February 28, 2011 was $3 million and $9 million, respectively.

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The weighted average fair value per share of the options granted during the nine months ended February 29, 2012 and February 28, 2011 as computed using the Black-Scholes pricing model was $22.14 and $17.67, respectively. The weighted average assumptions used to estimate these fair values are as follows:

	Nine Months Ended February 29 and 28,
	2012			2011
Dividend yield		1.4	%		1.6	%
Expected volatility		29.5	%		31.5	%
Weighted-average expected life (in years)		5.0			5.0
Risk-free interest rate		1.4	%		1.7	%