Year	% of total
1960	2.1583225189536237
1961	1.8734491315136474
1962	2.132111752064246
1963	1.7514414877778077
1964	1.736881005173688
1965	2.046316174119582
1966	1.8920916481892092
1967	1.868374299603678
1968	1.8117574949072488
1969	1.3509907265327907
1970	2.749274259900337
1971	2.2563527330773545
1972	1.976461305805773
1973	1.735233827525385
1974	2.3249443963580982
1975	2.0561249793354275
1976	1.5871025007718431
1977	1.7966490704613265
1978	1.6947385794077534
1979	1.5468506565768974
1980	1.9422693710156191
1981	1.8724425868972832
1982	1.3239862023991351
1983	1.34862038147841
1984	1.0598578826930025
1985	1.365157523846029
1986	1.1219922061742167
1987	1.1579835330698067
1988	1.263022942920943
1989	1.1226704065755413
1990	1.0541978201837592
1991	1.073624254113676
1992	1.1531368843113698
1993	1.129163220239947
1994	1.3001335393941211
1995	1.3769501320762978
1996	1.3676218536198423
1997	1.3914215773228795
1998	1.6402526088469926
1999	1.5392747194662895
2000	1.4709374607121404
2001	1.6177176613021063
2002	1.5993094688383775
2003	1.1139331640101593
2004	1.3647984267453295
2005	1.4167186966960394
2006	1.2701848672588392
2007	1.4814721499612624
2008	1.3909895934328744
2009	1.5715883298813533
2010	1.8588188861091486
2011	1.4290268394659082
2012	1.2596545689532561
2013	1.4869956469254126
2014	1.377217553688142
2015	1.1147552953918984