Year	% of total
1971	1.6867338599454689
1972	1.527048702690672
1973	3.194051340270845
1974	2.9826900752709973
1975	3.2407779002553836
1976	3.507166857804187
1977	2.356247999129092
1978	2.353370961686735
1979	2.2530286817812297
1980	2.1299550308219293
1981	2.0500424707707094
1982	1.3266463405389453
1983	2.1049993094344144
1984	2.1741705693754114
1985	2.436969516124319
1986	2.272799756411313
1987	2.1134487292510906
1988	2.092365492868483
1989	1.4537118585184499
1990	1.8621356704950218
1991	1.5694523442132107
1992	1.8123960667830623
1993	1.3716359295102092
1994	1.327223996088759
1995	1.685266906235335
1996	1.7955287299817955
1997	1.8727742351686203
1998	2.052240912769888
1999	2.1329329161428645
2000	2.826119840283913
2001	3.1391693054611607
2002	2.930339004017642
2003	2.541553222343424
2004	2.436635006012976
2005	2.3143080283897564
2006	2.2856129016680637
2007	2.0603566637919855
2008	1.6600181066884119
2009	2.005868006533571
2010	2.604820903386971
2011	3.0260223120263037
2012	2.8878018843529674
2013	2.855237545776392
2014	2.769764926288796