Year	Percent
1973-01-01	15.4205000000000000
1974-01-01	16.5094000000000000
1975-01-01	15.8591000000000000
1976-01-01	15.2080000000000000
1977-01-01	16.5099000000000000
1978-01-01	17.3022000000000000
1979-01-01	19.6889000000000000
1980-01-01	21.9862000000000000
1981-01-01	22.4311000000000000
1982-01-01	25.3517000000000000
1983-01-01	28.6158000000000000
1984-01-01	31.1029000000000000
1985-01-01	33.6656000000000000
1986-01-01	34.8281000000000000
1987-01-01	36.7363000000000000
1988-01-01	30.5005000000000000
1989-01-01	32.3479000000000000
1990-01-01	29.7092000000000000
1991-01-01	31.1963000000000000
1992-01-01	29.5365000000000000
1993-01-01	18.9740000000000000
1994-01-01	5.8238300000000000
1995-01-01	3.7685400000000002
1996-01-01	7.2896199999999990
1997-01-01	11.6474000000000000
1998-01-01	13.9842000000000000
1999-01-01	13.8964000000000000
2000-01-01	8.6352100000000000
2001-01-01	8.4838000000000000
2002-01-01	11.2014000000000000
2003-01-01	14.2410000000000000
2004-01-01	15.7384000000000000
2005-01-01	16.7341000000000000
2006-01-01	17.8980000000000000
2007-01-01	19.7753000000000000
2008-01-01	21.8862000000000000
2009-01-01	23.3454000000000000
2010-01-01	24.4809999999999980
2011-01-01	24.7877000000000000
2012-01-01	24.5257000000000000
2013-01-01	28.1656000000000000
2014-01-01	33.4688000000000000
2015-01-01	36.8344000000000000
2016-01-01	36.7112000000000000