Twelve seems to be the magic number for Costco Wholesale Corp., which saw 12 percent sales increases for the month, quarter, and year compared to its fiscal 2007 numbers.

Sales were $5.41 billion for the month, up 12 percent from last year's $4.84 billion. For the fiscal 2008 fourth quarter -- the 16 weeks ended August 31 - Costco's sales were $22.6 billion, also up 12 percent over last year's $20.09 billion. Sales for the 52-week fiscal year 2008 were $70.95 billion, also up 12 percent from $63.09 billion last year.

Gasoline price inflation continues to boost comps at Costco Wholesale Corp., which may not have hit 12 percent growth, but still reached a respectable 9 percent for the four weeks ended August 31. The average sales price per gallon is up 40 percent for the membership club compared to last year. Excluding gasoline price inflation, U.S. comparable sales would have been up 6 percent. Comps for the quarter were also 9 percent, and for the year hit 6 percent.

Costco ended its fiscal year with 543 warehouses in operation, including 398 in the United States and Puerto Rico, 75 in Canada, 20 in the United Kingdom, six in Korea, five in Taiwan, eight in Japan, and 31 in Mexico.