Year	Percent
1997-01-01	51.5900000000000000
1998-01-01	48.1542000000000000
1999-01-01	30.1721000000000000
2000-01-01	22.5225000000000000
2001-01-01	17.5592000000000000
2002-01-01	4.6693300000000000
2003-01-01	6.8890199999999995
2004-01-01	10.1479000000000000
2005-01-01	13.1345000000000000
2006-01-01	14.6371000000000000
2007-01-01	11.9662000000000000
2008-01-01	14.2242000000000000
2009-01-01	15.0352000000000000
2010-01-01	14.7520000000000000
2011-01-01	14.2249000000000000
2012-01-01	13.4187000000000000
2013-01-01	17.7554000000000000
2014-01-01	19.0417000000000000
2015-01-01	21.6101000000000000