Year	% of total
1970	1.5259281069396038
1971	1.4820422404853928
1972	1.4822813696569095
1973	1.4999954967404205
1974	1.4472273441022372
1975	1.6192609758574097
1976	1.5360496343179704
1977	1.431768723186319
1978	1.4587783810758066
1979	1.3918527922908088
1980	1.1740991091877206
1981	2.1230200317334393
1982	1.9040082208141198
1983	1.8667428280799343
1984	1.6488325055698658
1985	1.646381072777139
1986	1.927610512519362
1987	1.96982130209595
1988	1.5727779889532667
1989	1.8753971315561835
1990	7.641196013289036
1991	7.4074074074074066
1992	6.405693950177936
1993	8.085106382978724
1994	7.949790794979079
1995	7.792207792207792
1996	9.82905982905983
1997	8.550185873605948
1998	9.722222222222223
1999	11.158798283261802
2000	10.843373493975903
2001	11.688311688311687
2002	9.387755102040817
2003	10.212765957446807
2004	10.256410256410255
2005	9.523809523809524
2006	8.135593220338983
2007	8.038585209003216
2008	6.9364161849710975