Year	% of total
1970	4.989918173500066
1971	4.663255590407771
1972	4.642299371563236
1973	5.586669
1974	5.355556672617913
1975	6.9679955579722535
1976	7.294449554516609
1977	7.431307592837409
1978	6.789016728069301
1979	7.195383606821276
1980	7.836989247311828
1981	8.969859618528345
1982	9.09360996829807
1983	9.648344590491673
1984	7.529033651395508
1985	5.737745165263546
1986	4.890786800960851
1987	4.956364204279245
1988	4.542032352815516
1989	4.367332833791247
1990	4.166666666666666
1991	4
1992	4
1993	4.3478260869565215
1994	4.545454545454546
1995	4.3478260869565215
1996	4
1997	4
1998	8
1999	8
2000	7.142857142857142
2001	7.6923076923076925
2002	6.451612903225806
2003	6.666666666666667
2004	6.25
2005	6.0606060606060606
2006	9.090909090909092
2007	9.090909090909092
2008	8.823529411764707