Year	% of total
1970	51.1914069191041
1971	51.19798622450419
1972	51.562233415010425
1973	51.45208172296872
1974	51.50057670405772
1975	52.37174867169336
1976	52.97220688731703
1977	52.9875515427762
1978	52.46187943655969
1979	52.218767865643834
1980	52.2633214768927
1981	52.920998826051346
1982	53.48472851934132
1983	54.204627940243455
1984	54.96378175427691
1985	55.207129108842665
1986	55.3172977226785
1987	56.49480404288171
1988	55.20163003054917
1989	55.375058164051715
1990	68.75
1991	68.75
1992	62.5
1993	62.5
1994	68.75
1995	70.58823529411765
1996	64.70588235294117
1997	64.70588235294117
1998	64.70588235294117
1999	66.66666666666666
2000	64.70588235294117
2001	62.5
2002	58.82352941176471
2003	58.82352941176471
2004	58.82352941176471
2005	66.66666666666666
2006	61.111111111111114
2007	61.111111111111114
2008	58.82352941176471