Year	% of total
1960	1.0287498059776141
1961	1.3088165141593304
1962	1.2511732367927058
1963	1.2837712991154993
1964	1.6683636363636363
1965	2.2010420983268006
1966	2.2426557210352054
1967	3.2181569812481152
1968	4.676376569918506
1969	4.527079580808908
1970	3.059013326205659
1971	2.8949705409023903
1972	2.381290959545275
1973	3.3575112651389767
1974	3.6280267357988114
1975	3.6834127327847557
1976	4.4172087720474815
1977	4.277915447820983
1978	4.481098373611505
1979	4.101807245690735
1980	3.6964407224642226
1981	2.647390257644829
1982	2.803415008170926
1983	2.115832577299365
1984	1.430173222580719
1985	1.4767665850235776
1986	1.316177067012752
1987	2.0274137124985896
1988	2.3410657166919053
1989	3.6386569763949788
1990	3.416306911652743
1991	2.7799575582001372
1992	2.9972380203698403
1993	2.2566465645713256
1994	1.6945217780961104
1995	1.6421281952839706
1996	1.2549548024275259
1997	1.6361576011157601
1998	2.560674015265762
1999	2.0970903971879884
2000	1.829767699918758
2001	2.8644579334667166
2002	2.311206039011375
2003	3.6608078813723197
2004	3.869370608386887
2005	2.5154546802379922
2006	1.8524336920378077
2007	1.986761287982552
2008	1.6229706931532952
2009	1.733795897612545
2010	1.2950107310352137
2011	1.0372107203585605
2012	1.088194316823503
2013	1.1670888169020435
2014	1.2424852099350914
2015	1.2147777082028803