Year	Percent
1998-01-01	61.839000000000000
1999-01-01	61.443000000000005
2000-01-01	55.538999999999994
2001-01-01	58.688999999999990
2002-01-01	59.410000000000000
2003-01-01	61.935000000000000
2004-01-01	58.731000000000000
2005-01-01	57.379000000000000
2006-01-01	54.224000000000000
2007-01-01	50.841000000000000
2008-01-01	56.191000000000000
2009-01-01	60.306000000000004
2010-01-01	17.770000000000000
2011-01-01	19.370000000000000
2012-01-01	21.660000000000000
2013-01-01	23.530000000000000
2014-01-01	25.540000000000000
2015-01-01	27.430000000000000
2016-01-01	31.160000000000000