Compute trend percents for the following financial items, using 2007 as the base year.
2011 2010 2009 2008 2007
Sales $282,700 $270,700 $252,500 $234,460 $150,000
Cost of goods sold 128,100 121,980 115,180 106,340 67,000
Accounts receivable 18,000 17,200 16,300 15,100 9,000