Year	Percent
1998-01-01	37.710000000000000
1999-01-01	24.089500000000000
2000-01-01	31.200000000000000
2001-01-01	39.200000000000000
2002-01-01	32.943000000000005
2003-01-01	39.700000000000000
2004-01-01	48.517500000000000
2005-01-01	50.354800000000000
2006-01-01	53.929500000000000
2007-01-01	53.627300000000000
2008-01-01	40.775800000000000
2009-01-01	34.174400000000000
2010-01-01	45.850700000000000
2011-01-01	47.993900000000000
2012-01-01	43.649700000000000
2013-01-01	42.094600000000000
2014-01-01	41.821900000000000
2015-01-01	43.037600000000000
2016-01-01	48.741700000000000