Year	Percent
1960-01-01	4.0106199999999990
1961-01-01	3.8257300000000000
1962-01-01	4.4091600000000000
1963-01-01	6.1541100000000000
1964-01-01	6.2939300000000005
1965-01-01	6.8664300000000000
1966-01-01	7.0598199999999990
1967-01-01	7.5629800000000005
1968-01-01	7.4943300000000010
1969-01-01	8.1280700000000000
1970-01-01	7.4093000000000000
1971-01-01	8.8071700000000000
1972-01-01	8.1316800000000010
1973-01-01	8.7432199999999990
1974-01-01	9.6333000000000000
1975-01-01	10.2939000000000000
1976-01-01	11.2074000000000000
1977-01-01	12.7533000000000000
1978-01-01	13.5297000000000000
1979-01-01	13.1606000000000000
1980-01-01	13.3544000000000000
1981-01-01	13.1468000000000000
1982-01-01	13.7058000000000000
1983-01-01	14.2467000000000000
1984-01-01	14.4194000000000000
1985-01-01	14.8232000000000000
1986-01-01	14.5564000000000000
1987-01-01	13.5470000000000000
1988-01-01	12.4934000000000000
1989-01-01	13.6022000000000000
1990-01-01	14.8342000000000000
1991-01-01	14.4669000000000000
1992-01-01	13.7216000000000000
1993-01-01	11.9983000000000000
1994-01-01	13.3136000000000000
1995-01-01	11.7733000000000000
1996-01-01	10.4672000000000000
1997-01-01	9.4279600000000000
1998-01-01	8.9021200000000000
1999-01-01	9.0685600000000000
2000-01-01	10.0620000000000010
2001-01-01	11.3458000000000000
2002-01-01	12.2329000000000000
2003-01-01	12.8894000000000000
2004-01-01	12.8539000000000000
2005-01-01	13.2459000000000000
2006-01-01	14.0168000000000000
2007-01-01	14.6587000000000000
2008-01-01	15.5830000000000000
2009-01-01	16.2678000000000000
2010-01-01	16.8897000000000000
2011-01-01	17.7415000000000000
2012-01-01	16.6751000000000000
2013-01-01	15.7971000000000000
2014-01-01	16.5279000000000000
2015-01-01	17.0693000000000000
2016-01-01	17.1515000000000000