Year	% of merchandise exports
1978	24.928098409467104
2010	48.16991832845314
2011	48.536457338691
2012	47.5267534650177
2013	48.25955117793017
2015	37.226746688809726
2016	20.48635800514383
2017	20.516632352902786
2018	24.261256212941014
2019	21.187451104853928