Year	Percent
1960-01-01	14.1481000000000000
1961-01-01	14.0373000000000000
1962-01-01	13.7479000000000000
1963-01-01	13.2915000000000000
1964-01-01	13.4350000000000000
1965-01-01	12.9575000000000000
1966-01-01	13.6579000000000000
1967-01-01	14.0782000000000000
1968-01-01	13.6978000000000000
1969-01-01	12.9333000000000000
1970-01-01	12.9079000000000000
1971-01-01	13.7643000000000000
1972-01-01	13.0249000000000000
1973-01-01	11.2425000000000000
1974-01-01	9.2419500000000000
1975-01-01	9.5596400000000000
1976-01-01	12.8797000000000000
1977-01-01	16.1067000000000000
1978-01-01	17.0390000000000000
1979-01-01	17.6408000000000000
1980-01-01	21.7216000000000000
1981-01-01	26.6461000000000000
1982-01-01	27.8618000000000000
1983-01-01	33.1349000000000000
1984-01-01	21.9675000000000000
1985-01-01	30.6395000000000000
1986-01-01	41.2076000000000000
1987-01-01	32.4575000000000000
1988-01-01	30.5840000000000000
1989-01-01	29.5831000000000000
1990-01-01	30.1617000000000000
1991-01-01	31.6885000000000000
1992-01-01	32.3772000000000000
1993-01-01	27.1168000000000000
1994-01-01	20.6859000000000000
1995-01-01	16.1658000000000000
1996-01-01	11.4655000000000000
1997-01-01	8.9328399999999990
1998-01-01	7.6378699999999995
1999-01-01	7.9747699999999995
2000-01-01	8.5899399999999990
2001-01-01	9.5586200000000000
2002-01-01	10.6752000000000000
2003-01-01	11.3070000000000000
2004-01-01	11.0553000000000000
2005-01-01	10.5681000000000000
2006-01-01	7.8659600000000000
2007-01-01	6.1937500000000000
2008-01-01	6.4925000000000000
2009-01-01	7.5642500000000000
2010-01-01	7.0650500000000000
2011-01-01	7.1917899999999990
2012-01-01	8.4289700000000000
2013-01-01	9.6061700000000000
2014-01-01	10.7312000000000000
2015-01-01	12.6665000000000000
2016-01-01	15.0173000000000000