Securities and Exchange Commission

Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

Compare To Other Companies

Annual (pure)

Value	Reported On	Form	FY	FP	Start Date	End Date	Fiscal Period
0.4051	2012-02-24	10-K	2011	FY	2009-01-01	2009-12-31	CY2009
0.4294	2012-02-24	10-K	2011	FY	2010-01-01	2010-12-31	CY2010
0.4517	2012-02-24	10-K	2011	FY	2011-01-01	2011-12-31	CY2011

All Reported Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate (pure)

Value	Reported On	Form	FY	FP	Start Date	End Date	Fiscal Period
0.4051	2012-02-24	10-K	2011	FY	2009-01-01	2009-12-31	CY2009
0.4294	2012-02-24	10-K	2011	FY	2010-01-01	2010-12-31	CY2010
0.4108	2011-08-04	10-Q	2011	Q2	2011-01-01	2011-06-30
0.4108	2011-11-04	10-Q	2011	Q3	2011-01-01	2011-09-30
0.4517	2012-02-24	10-K	2011	FY	2011-01-01	2011-12-31	CY2011