Year	% of total
1990	36.54209206745507
1991	39.21172539288668
1992	41.26220697720027
1993	35.52169417677718
1994	31.401393266677967
1995	29.35463690579155
1996	34.42052965758857
1997	35.51179077810217
1998	39.492643578516585
1999	43.744331420594854
2000	48.63132866075177
2001	55.866779937375696
2002	61.94966556756667
2003	79.57172091322715
2004	84.47182732736046
2005	81.37617918218729
2006	84.19463955410886
2007	89.30915063194219
2008	93.86305129703041
2009	77.08555095771698
2010	103.42677911351524
2011	97.87608981767097
2012	94.03390902535345
2013	99.25953884643694
2014	103.64084581347221
2015	104.26847128587725
2016	102.02503600094649