Year	Percent
1998-01-01	13.600000000000000
1999-01-01	15.500000000000000
2000-01-01	12.300000000000000
2001-01-01	5.600000000000000
2002-01-01	7.400000000000000
2003-01-01	7.000000000000000
2004-01-01	7.000000000000000
2005-01-01	6.300000000000000
2006-01-01	5.400000000000000
2007-01-01	4.600000000000000
2008-01-01	4.700000000000000
2009-01-01	7.000000000000000
2010-01-01	9.117339999999999
2011-01-01	14.428300000000000
2012-01-01	23.270400000000000
2013-01-01	31.898900000000000
2014-01-01	33.775300000000000
2015-01-01	36.647400000000000
2016-01-01	36.298700000000000