Year	Percent of Total
1960-01-01	5.69441200590742
1961-01-01	5.86998737966374
1962-01-01	6.07779314582675
1963-01-01	6.31193715495567
1964-01-01	6.55934227869597
1965-01-01	6.81308013214989
1966-01-01	7.09749544263018
1967-01-01	7.36620658180159
1968-01-01	7.63114813407580
1969-01-01	7.90999972645495
1970-01-01	8.20928841508665
1971-01-01	8.50558993700655
1972-01-01	8.80604511569753
1973-01-01	9.10072040752141
1974-01-01	9.37376416643806
1975-01-01	9.61575103899210
1976-01-01	9.83127714059707
1977-01-01	10.02806905358640
1978-01-01	10.17888053740990
1979-01-01	10.24472279719230
1980-01-01	10.20969177862070
1981-01-01	10.07406505891460
1982-01-01	9.84109296071048
1983-01-01	9.57392887704980
1984-01-01	9.35930390750998
1985-01-01	9.24448318534680
1986-01-01	9.29067403682016
1987-01-01	9.41702324051203
1988-01-01	9.59504903666695
1989-01-01	9.78117809868068
1990-01-01	9.95125406957105
1991-01-01	10.18531739704790
1992-01-01	10.39405943326490
1993-01-01	10.58424293168430
1994-01-01	10.76704645817230
1995-01-01	10.94763552206260
1996-01-01	11.18740122191670
1997-01-01	11.41922424532410
1998-01-01	11.64003245599480
1999-01-01	11.84292629882910
2000-01-01	12.02483911036680
2001-01-01	12.29866417056070
2002-01-01	12.55808056818340
2003-01-01	12.78812729608340
2004-01-01	12.96491156151260
2005-01-01	13.07730802650680
2006-01-01	13.17997771369560
2007-01-01	13.21236585264360
2008-01-01	13.22618361799050
2009-01-01	13.29735495515050
2010-01-01	13.47239214305660
2011-01-01	13.75575869771690
2012-01-01	14.13955131198350
2013-01-01	14.60051463540940
2014-01-01	15.09893959897690
2015-01-01	15.61163652868530
2016-01-01	16.18696272879030
2017-01-01	16.76273683341300