Year	% of total
1970	19.985328548559632
1971	26.87313759322641
1972	23.899865974060567
1973	26.834019504601436
1974	26.80392120158666
1975	22.01544618403303
1976	21.000478751742406
1977	25.33401211914313
1978	22.449980565720868
1979	21.0264722320273
1980	19.665704148318515
1981	26.873238161112972
1982	28.350903114281046
1983	28.84716487391023
1984	37.510340325003206
1985	33.533362522541246
1986	32.6888542646457
1987	28.566731480300906
1988	27.73437782649354
1989	27.32341926709015
1990	88.88888888888889
1991	88.88888888888889
1992	89.47368421052632
1993	94.44444444444444
1994	94.44444444444444
1995	89.47368421052632
1996	90.47619047619048
1997	90.47619047619048
1998	95
1999	90.47619047619048
2000	90.47619047619048
2001	90.47619047619048
2002	90
2003	90
2004	92
2005	90
2006	91.66666666666666
2007	86.36363636363636
2008	89.28571428571429