Year	Percent
1960-01-01	13.128600000000000
1961-01-01	13.929200000000000
1962-01-01	15.945100000000000
1963-01-01	15.946100000000000
1964-01-01	16.176600000000000
1965-01-01	15.483100000000000
1966-01-01	16.429200000000000
1967-01-01	18.128100000000000
1968-01-01	19.346300000000000
1969-01-01	19.636900000000000
1970-01-01	16.988000000000000
1971-01-01	16.468000000000000
1972-01-01	16.308200000000000
1973-01-01	15.904400000000000
1974-01-01	14.363200000000000
1975-01-01	14.380999999999998
1976-01-01	16.590300000000000
1977-01-01	18.145800000000000
1978-01-01	19.601000000000000
1979-01-01	19.425800000000000
1980-01-01	20.432900000000000
1981-01-01	21.293900000000000
1982-01-01	22.480200000000000
1983-01-01	23.387900000000000
1984-01-01	22.683000000000003
1985-01-01	22.405700000000000
1986-01-01	21.683300000000000
1987-01-01	20.362800000000000
1988-01-01	21.386200000000000
1989-01-01	23.219000000000000
1990-01-01	24.496500000000000
1991-01-01	26.798800000000000
1992-01-01	28.705300000000000
1993-01-01	32.056300000000000
1994-01-01	36.203100000000000
1995-01-01	39.891200000000000
1996-01-01	43.755300000000000
1997-01-01	48.606700000000000
1998-01-01	52.266600000000000
1999-01-01	52.075200000000000
2000-01-01	51.783000000000000
2001-01-01	51.718200000000000
2002-01-01	51.545000000000000
2003-01-01	50.796800000000000
2004-01-01	48.538700000000000
2005-01-01	47.781900000000000
2006-01-01	49.309600000000000
2007-01-01	49.302100000000000
2008-01-01	49.445000000000000
2009-01-01	52.502100000000000
2010-01-01	51.057400000000000
2011-01-01	51.409000000000000
2012-01-01	49.990400000000000
2013-01-01	54.402400000000000
2014-01-01	60.457600000000000
2015-01-01	62.793800000000000
2016-01-01	64.148400000000000