Year	% of total
1960	0.6996565322478057
1961	0.6569837669033379
1962	0.3304744669132111
1963	0.5254071905726939
1964	0.39345294302801387
1965	0.1977800201816347
1966	0.34754875904648974
1967	0.18913149320250178
1968	0.16251264447871583
1969	0.40448579959725023
1970	0.6342712755900098
1971	0.4454728623599043
1972	0.25890637945318973
1973	0.221829684098098
1974	0.07305650137633231
1975	0.09173008100670534
1976	0.11703178144314816
1977	0.31695063044110117
1978	0.1645245487945175
1979	0.1643329881590203
1980	0.1635820895522388
1981	0.136616430546143
1982	0.2888958358036802
1983	0.30280447886500206
1984	0.30782264896921774
1985	0.328047581500842
1986	0.42724432582293675
1987	0.470121287438706
1988	0.38506567153257965
1989	0.37174408531610864
1990	0.07236187515931947
1991	0.08501940070367121
1992	0.08026504542660018
1993	0.0826943316794467
1994	0.2252432716362633
1995	0.22332749791397394
1996	0.354352518672754
1997	0.2932285915977338
1998	0.2645343594060001
1999	0.30502015749834405
2000	0.20489646413259327
2001	0.2827070643797341
2002	0.2710380835380835
2003	0.43124056661260535
2004	0.46136939522464515
2005	0.38617071660169766
2006	0.5254821732028839
2007	0.6876689784883037
2008	0.42918758897143705
2009	3.330304858030677
2010	4.05800159041854
2011	3.3655139669225296
2012	1.9291617795477483
2013	1.9829731107047572
2014	1.9706003143897015
2015	1.9302121982740652