Tropical Island produces only banana, mango and coconut. In the base year 2020, the Island produced 1,200 bunches of bananas, 1,350 boxes of mango and 1,150 boxes of coconut. The prices were $4.2 for a bunch of bananas, $6.5 for a box of mango and $5.5 for a box of coconut in 2015. However, in 2021, the Island produced 1,325 bunches of bananas, 1,400 boxes of mango and 1,140 boxes of coconut, and the corresponding prices were $4.5 for a bunch of bananas, $6.3 for a box of mango and $5.8 for a box of coconut.

(i)Calculate Tropical Island's real GDP in 2020 and 2021. Calculate the growth rate of real GDP between the two years and interpret what it means.