The per capita disposable income (in dollars per year) in the United States for selected years from 2014 and projected to 2040 can be modeled by

I(t) = 0.5532t² + 738.5t + 34,430

where t is the number of years past 2010. Use n = 10 equal subdivisions with right-hand endpoints to approximate (to the nearest 10 units) the area under the graph of I(t) between t = 8 and t = 13. What does this area represent?