Year	Percent
1996-01-01	33.713600000000000
1997-01-01	31.454400000000000
1998-01-01	28.754800000000000
1999-01-01	27.543500000000000
2000-01-01	28.730700000000000
2001-01-01	31.067200000000000
2002-01-01	32.770700000000000
2003-01-01	34.358300000000000
2004-01-01	34.037100000000000
2005-01-01	35.303300000000000
2006-01-01	37.479300000000000
2007-01-01	36.193400000000000
2008-01-01	28.329800000000000
2009-01-01	30.429700000000000
2010-01-01	30.458000000000002
2011-01-01	30.606600000000000
2012-01-01	28.481800000000000
2013-01-01	23.032500000000000
2014-01-01	21.935800000000000
2015-01-01	20.618800000000000
2016-01-01	19.406300000000000