Year	% of total
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	1.9959720090364885
1985	2.541751086946524
1986	4.041989049785015
1987	2.752154430709491
1988	4.479789770483403
1989	4.567542306979111
1990	3.3813978503549196
1991	3.608325223308161
1992	3.68083148995309
1993	2.7863310717789913
1994	3.6108742707257333
1995	4.068445273792527
1996	4.0074923913625975
1997	4.150619733082971
1998	4.492429095221132
1999	4.191635080882395
2000	4.092803328745063
2001	3.2926244424462325
2002	3.4597211314679197
2003	3.542582274070468
2004	3.5282999481392405
2005	2.930971724368607
2006	2.501648922823336
2007	2.7387111385062015
2008	3.1820999648484625
2009	3.1742160423430135
2010	2.817550576781765
2011	3.06346033640616
2012	2.7044919723537904
2013	3.129587158102133
2014	2.987877759554556