Taxes:
Along with incomes, peoples charitable contributions have steadily increased over the past few years. The table shows the average deduction for charitable contributions reported on individual income tax returns for the period 2007 to 2012. Find the average rate of change between 2009 and 2011.
(Year)2007 (charitable contributions) $1980
(Year)2008 (charitable contributions) $2350
(Year)2009 (charitable contributions) $2490
(Year)2010 (charitable contributions) $2760
(Year)2011 (charitable contributions) $3060
(Year)2012 (charitable contributions) $3120