Year	% of total
1960	0.8297644539614561
1961	3.491872366044552
1962	0.8799171842650102
1963	1.434195725534308
1964	1.6675218060543866
1965	1.6566265060240966
1966	1.1108427915962327
1967	1.559953434225844
1968	0.9604390578550195
1969	1.0622477161674102
1970	0.9230164964650431
1971	0.7106788853562745
1972	0.6699576868829338
1973	0.5402750491159135
1974	0.5441741357234315
1975	0.5554802872239534
1976	0.4714439655172414
1977	0.7982040409079569
1978	0.7886246863424543
1979	0.6359851988899167
1980	0.8057923624897816
1981	0.7725898555592879
1982	0.9975591637482752
1983	0.7727975270479135
1984	0.8210549994376336
1985	0.844214317874831
1986	0.7865414026655014
1987	0.8316232854519927
1988	0.8540852027166084
1989	1.2415349887133182
1990	1.5533747528946624
1991	1.363594604447685
1992	0.7802127659574468
1993	1.0951717272274766
1994	1.0860157334567329
1995	0.9374046793760832
1996	0.27835797043547744
1997	0.2676642335766424
1998	0.3265602968460111
1999	0.32941070786920584
2000	0.29908156028368793
2001	0.24275836704670833
2002	0.2683859784283513
2003	0.3924256837098692
2004	0.4111974369243092
2005	0.29778422273781907
2006	0.09760076045627376
2007	0.2696323529411765
2008	0.3484416571645762
2009	0.32475276752767523
2010	0.25448446794448115
2011	0.03854590049053959
2012	0.05084228769497401
2013	0.1340767824497258
2014	0.013642113095238096
2015	0.0800363768643143
2016	0.02577855887521968