Year	% of total
1970	40.065849546431124
1971	37.98113143610938
1972	45.801120107451624
1973	40.76308421016502
1974	37.30440463924335
1975	37.44137191464612
1976	41.882903991629185
1977	44.7184896238115
1978	38.600485409017054
1979	42.07060136577408
1980	41.17829491904461
1981	39.212609362950616
1982	47.2192467037768
1983	41.391525444785266
1984	32.69213577838843
1985	32.393688919898736
1986	39.45334271376141
1987	43.032442112851534
1988	28.08361095823249
1989	29.882448462059774
1990	95.04950495049505
1991	95.06578947368422
1992	95.08196721311475
1993	95.09803921568627
1994	95.11400651465797
1995	95.16616314199395
1996	95.07692307692308
1997	95.23809523809523
1998	95.16616314199395
1999	95.3623188405797
2000	95.27777777777777
2001	95.38043478260869
2002	95.26315789473684
2003	95.02617801047121
2004	95.22613065326632
2005	95.01312335958005
2006	95.05208333333334
2007	94.6524064171123
2008	94.5945945945946