Year	Percent
1985-01-01	18.483800000000000
1986-01-01	18.567900000000000
1987-01-01	20.002300000000000
1988-01-01	18.577700000000000
1989-01-01	17.598500000000000
1990-01-01	17.695500000000000
1991-01-01	19.704500000000000
1992-01-01	21.182300000000000
1993-01-01	22.598000000000003
1994-01-01	22.980999999999998
1995-01-01	22.718100000000000
1996-01-01	23.838400000000000
1997-01-01	26.771900000000000
1998-01-01	29.481700000000000
1999-01-01	32.340000000000000
2000-01-01	35.148500000000000
2001-01-01	37.135600000000000
2002-01-01	39.811400000000000
2003-01-01	42.300100000000000
2004-01-01	42.777100000000000
2005-01-01	41.739100000000000
2006-01-01	40.972700000000000
2007-01-01	40.468900000000000
2008-01-01	40.415600000000000
2009-01-01	44.807500000000000
2010-01-01	49.065800000000000
2011-01-01	47.813500000000000
2012-01-01	45.657800000000000
2013-01-01	44.736700000000000
2014-01-01	43.885800000000000
2015-01-01	44.801800000000000
2016-01-01	50.799200000000000