Year	% of total
1960	26.100366253293068
1961	22.244191794364802
1962	14.876313114198576
1963	23.35094930514778
1964	19.830266908525527
1965	22.326114495988417
1966	18.621399176954732
1967	19.829507466012924
1968	20.56539471478854
1969	23.288690476190478
1970	23.036443220380658
1971	17.044721880311823
1972	22.314679167887487
1973	20.12682657843948
1974	41.456391234320854
1975	50.41659483997012
1976	45.93298375751375
1977	47.134637514384345
1978	52.1567371343156
1979	50.71117283654998
1980	54.878442775220094
1981	58.07416267942585
1982	57.19613693467337
1983	56.19756587498523
1984	52.236340033830295
1985	57.43147833013504
1986	54.04934882319462
1987	52.66809846357179
1988	52.87428932406822
1989	55.836280949974736
1990	66.33813518231186
1991	59.06810333040335
1992	70.48341575178996
1993	62.92231069547848
1994	57.5492658388471
1995	51.32043954164529
1996	35.7632856158616
1997	40.86494224968734
1998	58.486048898279506
1999	71.07329463445247
2000	63.14585460227696
2001	73.39341976837352
2002	86.31480217062784
2003	92.53266908037654
2004	61.39155037130447
2005	60.70319730913245
2006	65.52111148175328
2007	56.133086136928924
2008	62.60748119151018
2009	64.1104251814799
2010	66.48951341890314
2011	59.30593548007992
2012	62.74352036100691
2013	55.28830935635124
2014	55.338894611096364
2015	51.16464630779848
2016	47.497221399481674