Year	% of total
1960	48.37988826815642
1961	50.52334943639292
1962	48.943794794417194
1963	49.284112471968264
1964	50.523648648648646
1965	48.982534850184265
1966	52.36386331721017
1967	49.910979228486646
1968	53.74224672639559
1969	51.88913583474963
1970	61.17996385231087
1971	59.758162031438935
1972	59.09143855562027
1973	58.11751904243743
1974	59.559710494571775
1975	57.19685361119624
1976	57.33127948397034
1977	57.221393961982855
1978	54.11278261634557
1979	53.189733432367746
1980	53.93518518518518
1981	51.8063345430551
1982	51.29781966296621
1983	51.0641453466815
1984	50.3481320655836
1985	51.69408019404229
1986	53.271097834204625
1987	53.42097617664149
1988	53.96448049223884
1989	55.28001653234139
1990	63.72594555873925
1991	63.31338671411625
1992	67.05489569629769
1993	64.65569200430261
1994	70.16232323232323
1995	53.874972908906194
1996	55.4006745964316
1997	54.76568485610945
1998	55.21383991262287
1999	54.4438249507786
2000	50.41337684644452
2001	48.780618169398906
2002	50.940303030303035
2003	52.96268654052124
2004	52.5590288153682
2005	53.469431877050596
2006	58.90579348579349
2007	57.90749957763136
2008	56.801829999999995
2009	56.80471886912325
2010	55.23744743351886
2011	50.59106708625375
2012	55.40931426945511
2013	58.50983931096542
2014	53.116830368328735
2015	54.25150684931507
2016	58.7350429799427