Year	% of total
1970	10.421310137980527
1971	9.789381991954924
1972	9.680577260290674
1973	9.349669257452375
1974	9.174454510281997
1975	8.987225226561657
1976	10.127827825669023
1977	10.321163408158341
1978	10.74235985667328
1979	10.8236671694466
1980	10.481026422615297
1981	10.497841989859987
1982	10.733419906620014
1983	9.832993635635898
1984	10.42539612768735
1985	7.685073520943746
1986	7.58465588616347
1987	7.559636182928584
1988	7.58381145899642
1989	12.747253430014545
1990	0
1991	0
1992	0
1993	0
1994	0
1995	0
1996	0
1997	0
1998	0
1999	0
2000	0
2001	0
2002	0
2003	0
2004	100
2005	50
2006	50
2007	50
2008	50