Year	% of total
1970	75.46991339258857
1971	76.99387350324855
1972	76.184805173297
1973	74.99061868941841
1974	75.7771807022074
1975	71.89227864848493
1976	69.02814102722282
1977	67.01194215451905
1978	66.36140582851043
1979	69.74488638004811
1980	65.00952343213399
1981	61.26821220229372
1982	56.5566519987317
1983	49.376830660577745
1984	40.38768436882611
1985	44.83077486530333
1986	38.55806529999643
1987	41.41001703357818
1988	46.2280315503312
1989	46.14256013922089
1990	72.3404255319149
1991	75.86206896551724
1992	78.125
1993	76.5625
1994	72.41379310344827
1995	73.77049180327869
1996	71.1864406779661
1997	73.33333333333333
1998	71.1864406779661
1999	71.1864406779661
2000	69.81132075471697
2001	67.27272727272727
2002	67.24137931034483
2003	66.66666666666666
2004	69.56521739130434
2005	70.27027027027027
2006	44.79166666666667
2007	54.310344827586206
2008	53.50877192982456