Year	% of total
1970	17.63479255458824
1971	15.548787933554129
1972	13.927993968183008
1973	12.886982089866498
1974	11.18080139562282
1975	5.509612261470838
1976	5.528617717728042
1977	6.791095275334734
1978	5.066654894941816
1979	3.4448990612986474
1980	3.125042914986503
1981	3.232280516305968
1982	0.8595327469909259
1983	0.9633042376838972
1984	1.0484847804203608
1985	1.8051421830704018
1986	1.952331069283254
1987	2.3590918638074734
1988	2.3340385207417635
1989	2.498587209721783
1990	35.714285714285715
1991	40
1992	37.5
1993	38.88888888888889
1994	45.45454545454545
1995	43.47826086956522
1996	40
1997	40
1998	40
1999	40
2000	38.095238095238095
2001	28.57142857142857
2002	29.166666666666668
2003	25.925925925925924
2004	24.137931034482758
2005	19.35483870967742
2006	16.216216216216218
2007	13.461538461538462
2008	12.068965517241379