Year	Percent
1991-01-01	54.483000000000004
1992-01-01	64.973700000000000
1993-01-01	67.004300000000000
1994-01-01	65.114700000000000
1995-01-01	52.334900000000000
1996-01-01	49.644600000000000
1997-01-01	32.839900000000000
1998-01-01	24.571200000000000
1999-01-01	28.240100000000000
2000-01-01	30.969400000000000
2001-01-01	35.923900000000000
2002-01-01	39.292900000000000
2003-01-01	41.550400000000000
2004-01-01	45.769300000000000
2005-01-01	49.713000000000000
2006-01-01	55.390300000000000
2007-01-01	59.503100000000000
2008-01-01	63.135500000000000
2009-01-01	65.166000000000000
2010-01-01	65.893400000000000
2011-01-01	67.058700000000000
2012-01-01	72.367100000000000
2013-01-01	78.309800000000000
2014-01-01	80.506200000000000
2015-01-01	80.224300000000000
2016-01-01	81.103100000000000