Exhibit 12.1

Computation of Ratio of Earnings to Fixed Charges

(Dollars in thousands, except Ratio Data)

	Years Ended July 31,
	2011		2010		2009		2008		2007
Earnings:
Income before income taxes	$	144,058		109,402		97,272	$	186,187	$	151,928
Add back:
Fixed charges less interest capitalized		24,012		23,248		27,128		29,059		25,156
Less:
Preferential stock dividends and premium on redemption of preferred stock		—		—		—		—		—
Total earnings	$	168,070		132,650	$	124,400	$	215,246	$	177,084
Fixed Charges:
Interest, capitalized and expensed	$	21,777		20,852		24,541	$	26,385	$	22,936
Amortization of debt expense		347		379		379		341		284
Interest portion of rent expense		1,888		2,017		2,208		2,333		1,936
Preferential stock dividends and premium on redemption of preferred stock		—		—		—		—		—
Total Fixed Charges	$	24,012		23,248	$	27,128	$	29,059	$	25,156
Ratio of Earnings to Fixed Charges (1)		7.0		5.7		4.6		7.4		7.0

(1) The ratio of earnings to fixed charges has been computed by adding income before income taxes and fixed charges less interest capitalized and subtracting preferred stock dividends and premium on redemption of preferred stock to derive total earnings, and dividing total earnings by fixed charges. Fixed charges consist of interest expensed and capitalized, amortization of debt expense, 8.5% of rent expense which is deemed representative of an interest factor and preferred stock dividends and premium on redemption of preferred stock. Interest excludes uncertain tax positions which is included in income tax expense.