Year	% of total
1971	0.11580818230871798
1972	0.10103978392284332
1973	0.20213520214659614
1974	0.3256711838329429
1975	0.5305532905215335
1976	0.6755400957289975
1977	0.5606128250906782
1978	0.5936478463807054
1979	0.551674131050772
1980	0.49971245735889785
1981	0.6260553532300859
1982	0.5792692403201858
1983	0.716726475151696
1984	0.9293420834534836
1985	1.051587336225159
1986	0.9585033876301536
1987	0.8786983063638291
1988	1.0194120812850715
1989	0.9299448997032228
1990	5.643700052718857
1991	5.520172263741976
1992	5.4200967057353
1993	5.350245142813819
1994	4.998398108315981
1995	5.076024784609249
1996	5.40763261034365
1997	5.39020700368651
1998	5.114837099459775
1999	5.202431916044507
2000	5.331676597708934
2001	5.427563749929654
2002	5.401738497915458
2003	5.421659617348505
2004	5.113899130949992
2005	4.891601851224974
2006	4.707663739610954
2007	4.471728542218794
2008	4.41803382794398
2009	4.288787690038936
2010	4.129585096573699
2011	4.118870035135061
2012	4.059569584133162
2013	3.9270581859754126
2014	4.058548429224606
2015	0.08760740219596856