Year	% of total
1960	0.6153995136834267
1961	0.6271742524594005
1962	0.5912525400638748
1963	0.5942166207864028
1964	0.5509686436432566
1965	0.5601943120876007
1966	0.7174253889724064
1967	0.7367111198257923
1968	0.7574616075785894
1969	0.7439658495556735
1970	0.967796698531755
1971	0.9358149743668002
1972	0.8372977062896843
1973	0.8043650029265832
1974	0.630457273324637
1975	0.6955269540871144
1976	0.6350962878826613
1977	0.64050810293786
1978	0.6520361736330397
1979	0.6235580714525216
1980	0.7386052501663626
1981	0.7255358833505098
1982	0.6340171221290113
1983	0.6084020600860014
1984	0.6011344036097709
1985	0.6242728260647682
1986	0.6591554515570351
1987	0.6227217180900884
1988	0.6429523000858404
1989	0.6121297736342179
1990	0.8831542745628895
1991	0.9088770784213801
1992	0.9546126549853087
1993	1.0499414608057065
1994	1.1140178092857982
1995	1.2176695738800596
1996	1.2130645397747304
1997	1.4606812152966573
1998	1.7033304509366285
1999	1.8409616940482882
2000	2.1910907195472613
2001	2.4159716297102465
2002	2.979584912998327
2003	3.467204595770127
2004	4.1814723401226015
2005	4.905038302696226
2006	5.667613847687343
2007	6.749344891037806
2008	7.681822300984756
2009	9.068944017865784
2010	10.003522143896049
2011	12.289649308730224
2012	14.433570165089233
2013	15.998560980829899
2014	17.249322021336347
2015	18.73944232148645