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	1.4799660879501642
1976	1.4999053958752602
1977	1.4874927083690765
1978	1.9660367556334828
1979	1.715686274509804
1980	1.5801006079683981
1981	1.6939097310040123
1982	0.4393818808860591
1983	0.38725901089689857
1984	0.027079550160884387
1985	0.7005893847204792
1986	0.8249203371154592
1987	1.0289539455414431
1988	1.2225079369639855
1989	1.2635181382614646
1990	1.0018341485104492
1991	1.1171757367175736
1992	1.1325834552208862
1993	1.3154654674114492
1994	1.449910476166627
1995	1.6225806054184582
1996	2.0322395607740305
1997	2.2248419495394285
1998	2.432091313175657
1999	2.7871309963099633
2000	3.1573897423882364
2001	3.4004889871133743
2002	4.025796772277847
2003	4.017847920841166
2004	5.149485249076215
2005	7.362816625133855
2006	8.03881294709257
2007	7.108828983026673
2008	8.76692204700982
2009	9.444898892612432
2010	9.299907772281378
2011	10.76226494564025
2012	12.013785358864643
2013	11.863057324840764
2014	11.21274826432536
2015	12.35759062414827