Year	% of total
1960	0
1961	0
1962	0
1963	0
1964	0
1965	0
1966	0
1967	0
1968	0
1969	0
1970	0
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	0
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	0
1990	0
1991	0
1992	0
1993	0
1994	0
1995	0
1996	0
1997	0.2607523731395758
1998	5.186727324131904
1999	18.814372931910334
2000	16.457622429217007
2001	15.621209495754634
2002	19.796276013143483
2003	16.637647514025925
2004	26.07580252972539
2005	29.457867844461767
2006	25.40966732542819
2007	27.985329239167523
2008	33.42275975810885
2009	29.73202376621802
2010	27.75139222588516
2011	28.746530989824237
2012	23.411444619975423
2013	14.303241382039813
2014	13.152678073096094
2015	20.596322224605604