Exhibit 12.1

COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES

(in thousands, except ratios)

	Historical
	Years Ended September 30,
	2007			2008			2009			2010			2011
Pre-tax income	$	159,959		$	244,775		$	296,431		$	319,979		$	324,847
Interest expense		1,689			1,410			2,293			2,725			4,530
Captialized interest		2,641			2,606			8,786			3,937			8,218
Earnings	$	161,648		$	246,185		$	298,724		$	322,704		$	329,377
Ratio of earnings to fixed charges		37.3	x		61.3	x		27.0	x		48.4	x		25.8	x

For purposes of this table, “earnings” consists of income before income taxes plus fixed charges and less capitalized interest. “Fixed charges” consists of interest expense and capitalized interest.