Year	Percent
1980-01-01	15.844500000000000
1981-01-01	14.907400000000000
1982-01-01	13.345500000000000
1983-01-01	11.620200000000000
1984-01-01	11.048300000000000
1985-01-01	12.189900000000000
1986-01-01	15.600300000000000
1987-01-01	19.370900000000000
1988-01-01	20.380400000000000
1989-01-01	20.117700000000000
1990-01-01	16.370200000000000
1991-01-01	16.033400000000000
1992-01-01	15.017500000000000
1993-01-01	15.889900000000000
1994-01-01	14.748200000000000
1995-01-01	12.033500000000000
1996-01-01	11.264900000000000
1997-01-01	13.095100000000000
1998-01-01	17.853600000000000
1999-01-01	18.487400000000000
2000-01-01	21.594900000000000
2001-01-01	22.136900000000000
2002-01-01	23.414800000000000
2003-01-01	26.795500000000000
2004-01-01	28.194200000000000
2005-01-01	24.939500000000000
2006-01-01	31.504600000000000
2007-01-01	34.847200000000000
2008-01-01	35.320600000000000
2009-01-01	46.614700000000000
2010-01-01	45.935800000000000
2011-01-01	46.732200000000000
2012-01-01	51.517800000000000
2013-01-01	53.729100000000000
2014-01-01	51.413999999999994
2015-01-01	60.243200000000000