Year	% of total
1970	42.729265293944934
1971	42.379260095775315
1972	41.97415515139147
1973	41.30943469851983
1974	41.11490734868024
1975	40.48514019653393
1976	40.385268209816985
1977	39.480934843345416
1978	39.62960390592599
1979	39.3008914116701
1980	39.344941583811945
1981	38.87200663791786
1982	38.26755147977907
1983	38.50816544462427
1984	37.93747806215383
1985	37.967788834190586
1986	37.387471164738315
1987	36.999788828816484
1988	35.823647593033286
1989	34.2792814139746
1990	14.285714285714285
1991	14.285714285714285
1992	14.285714285714285
1993	14.285714285714285
1994	14.285714285714285
1995	14.285714285714285
1996	14.285714285714285
1997	14.285714285714285
1998	14.285714285714285
1999	14.285714285714285
2000	14.285714285714285
2001	14.285714285714285
2002	14.285714285714285
2003	14.285714285714285
2004	12.5
2005	12.5
2006	12.5
2007	12.5
2008	12.5