Year	% of total
1965	13.348841370671916
1966	14.374841918893855
1967	13.12249799839872
1968	14.67882934245534
1969	17.755348638851377
1970	19.859716682712143
1971	22.235560891023077
1972	20.994915150401276
1973	17.190953919401462
1974	21.401106136423493
1975	23.808128175068386
1976	19.931972789115644
1977	22.80146995983249
1978	26.90756763105352
1979	19.96003099637016
1980	13.888423521527892
1981	12.127572016460904
1982	11.874873864783048
1983	12.326483132997286
1984	14.990685473139944
1985	16.957754888789374
1986	13.982326111744584
1987	11.899559649063834
1988	6.18821195224575
1989	5.20604442040499
1990	4.751019834013222
1991	9.434969796081834
1992	12.599021619062647
1993	17.080358499164515
1994	16.479188423094136
1995	15.532953142453994
1996	12.85836420632659
1997	16.557900387038448
1998	16.033880075289055
1999	14.033093677310212
2000	12.514563382683072
2001	11.511739667719347
2002	5.910335481372901
2003	4.76204422316591
2004	2.293224160436692
2005	1.2725137039937353
2006	1.4529127973451574
2007	1.3388388388388388
2008	0.886945658963148
2009	1.762838364709814
2010	1.3111771159455192
2011	0.39978900024986813
2012	0.534141764111448
2013	0.25747672806496336
2014	0.25857376156777356
2015	0.25377364708984246