Year	% of merchandise exports
1970	4.003410278294667
1971	4.007776409621821
1972	3.523465616330998
1973	2.273070729944866
1974	2.712464982441123
1975	8.560130540258553
1980	0.8883801959254386
1981	0.07030379436186865
1990	0.10624349006233343
1991	0.037004536555758916
1994	0.000207387309594335
2000	0.04293131319964055
2006	0.43031580998798963
2007	0.002875690679876475
2009	0.7121755162474387
2010	0.14957972379241072
2011	1.569238075068255