Assume that Indonesia only produces 3 commodities, namely palm oil, coffee and cocoa with production data as follows: + Year Price amount Coffee amount Price amount Coconut Production Price Production Cocoa Production Palm oil Coconut (IDR/kg) Coffee (kg) (IDR/kg) Cocoa (kg) (IDR/Kg) Palm oil (kg) 2018 1000 500 1500 345 500 450 2019 1500 375 2500 460 750 500 2020 2000 450 3500 375 1000 475 Based on the data above, calculate nominal gross domestic product and real gross domestic product (with a base year 2018) from 2018 to 2020, then explain what indicators are best used to measure economic performance