Year	% of total
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	9.588987979837146
1984	14.317758430597271
1985	24.18271383788625
1986	26.45381984036488
1987	36.92897240243369
1988	45.992542674374846
1989	46.95919678171799
1990	48.28738219158813
1991	45.80983212628909
1992	44.071327126400504
1993	41.91402096308674
1994	41.91854393555124
1995	41.23111294020813
1996	40.41037332573383
1997	39.460971268751585
1998	37.50739446087658
1999	37.259462888559945
2000	40.294393452871475
2001	38.7917067142661
2002	38.5900378903117
2003	32.25362424952409
2004	35.34769194256556
2005	38.69001006824029
2006	37.538693215092444
2007	36.729229229229226
2008	37.021861336664585
2009	42.95978612008466
2010	42.17441331513741
2011	43.54646158971654
2012	45.59838313844377
2013	50.73611936357034
2014	53.242378878606424
2015	52.185089974293064