Year	% of total
1990	44.9414719326972
1991	48.46445992121203
1992	44.8954553328228
1993	51.08190569344967
1994	50.833046021464106
1995	50.69988996652535
1996	51.67327443828657
1997	55.333495467449836
1998	46.233679667572765
1999	47.42604656618814
2000	53.28880296150557
2001	50.416695424023715
2002	50.0815349083061
2003	53.96650331068454
2004	58.64819624755809
2005	51.2171126365792
2006	53.4601713409719
2007	58.89190243437637
2008	59.411165712285026
2009	58.6700711163659
2010	64.87828937419326
2011	70.75922590004753
2012	74.9534247483714
2013	67.46225767843232
2014	80.04144164063447
2015	79.8139305837146
2016	76.7262324919155