Year	% of total
1973	100
1974	100
1975	100
1976	100
1977	100
1978	100
1979	100
1980	100
1981	100
1982	100
1983	100
1984	100
1985	100
1986	100
1987	100
1988	100
1989	100
1990	100
1991	100
1992	100
1993	100
1994	100
1995	100
1996	100
1997	96.61016949152543
1998	97.46835443037975
1999	97.22222222222221
2000	97.61904761904762
2001	96.96969696969697
2002	96.82539682539682
2003	97.5
2004	98.76543209876543
2005	99.06542056074767
2006	97.40259740259741
2007	98.63636363636363
2008	98.68995633187772
2009	99.21875
2010	99.1304347826087
2011	100
2012	100
2013	100
2014	100
2015	94.44444444444444