Year	% of total
1990	55.660137086288934
1991	47.87297684413122
1992	52.16149826307057
1993	49.213575280354995
1994	42.675085497326876
1995	41.404593018517964
1996	42.53737978869878
1997	46.11234910026267
1998	42.99298513796536
1999	43.40831711743168
2000	47.37808149283583
2001	49.68516395332745
2002	49.94429668298044
2003	46.99607820113643
2004	44.147626679605224
2005	46.56293357986328
2006	44.74830976586364
2007	45.21919850755496
2008	45.228721617354786
2009	45.354492003316146
2010	63.363457084020794
2011	65.81561716208809
2012	60.518260127499275
2013	60.82106843334156
2014	62.978967268935364
2015	60.07133088160198
2016	62.63844611900345