Refer to the following data. If Year 1 is the first year of this nation's existence and Year 5 is the present year, calculate the following:

Government spendingTax revenuesGDP

Year 1$450$425$2,000

Year 25004503,000

Year 36006504,000

Year 46406205,000

Year 56805804,800

If the MPC is 0.80 and full employment GDP for Year 5 is $5,000, then how much of a tax reduction is required to eliminate the GDP gap?