Year	% of merchandise exports
1975	95.35277496995205
1976	92.61582829592477
1977	88.99237384767002
1978	91.95332242201725
1979	91.70304981817944
1980	88.46474801708646
1999	58.729449717312995
2000	49.992973141012634
2001	59.05339876831711
2002	53.25980358478143
2003	40.12747843027069
2004	30.17956005968475
2005	23.332956238270107
2006	10.526095890485584
2016	36.7981102669428
2017	41.55739787249729
2018	29.79621860106037