Year	% of total
1960	0.8695652173913043
1961	0.8536025699862322
1962	1.15334329473291
1963	1.1932441324851941
1964	1.452513966480447
1965	2.081021087680355
1966	2.4611261944219174
1967	3.1217481789802286
1968	4.524592298427786
1969	5.758842115992254
1970	6.038647342995169
1971	9.348641801096822
1972	11.198594686157032
1973	7.072819621370563
1974	6.104792194490863
1975	4.055468949952303
1976	6.101751274661938
1977	4.395293092176945
1978	4.437869822485207
1979	3.9898823270647754
1980	1.7664763881681371
1981	1.1324613188254813
1982	1.241715548106955
1983	1.2817319666634737
1984	1.1643628291796992
1985	1.0173397914903577
1986	1.0611768451212393
1987	1.0375031890466877
1988	0.9752337544823889
1989	1.138625834899254
1990	1.374745417515275
1991	1.8001547007945995
1992	2.1213472355604335
1993	1.3374958922116331
1994	1.4292265362274534
1995	1.7478473203958358
1996	2.10129597696041
1997	1.8518518518518516
1998	2.393104776579353
1999	1.7444992937544597
2000	1.639344262295082
2001	1.5367727771679474
2002	1.7032001833040555
2003	1.7889908256880735
2004	1.794410083770453
2005	1.8757895101143816
2006	1.5852323934595083
2007	1.3787082888062734
2008	1.2754340951130736
2009	1.2208840160184782
2010	1.6592987343305272
2011	1.621931052029004
2012	1.4235397710595832
2013	1.1859720605355064
2014	0.8031154603292345
2015	1.0696400744360561