Year	Percent
1997-01-01	12.7341000000000000
1998-01-01	11.2061000000000000
1999-01-01	9.3222700000000000
2000-01-01	9.0829700000000000
2001-01-01	9.4695800000000000
2002-01-01	10.2364000000000000
2003-01-01	8.9171600000000000
2004-01-01	8.1006500000000000
2005-01-01	7.4679199999999994
2006-01-01	6.7497899999999990
2007-01-01	6.5941600000000005
2008-01-01	7.5776100000000010
2009-01-01	6.9732800000000000
2010-01-01	6.5750600000000010
2011-01-01	6.2396600000000000
2012-01-01	5.5795000000000000
2013-01-01	4.9528500000000000
2014-01-01	4.3951500000000000
2015-01-01	3.4713300000000005
2016-01-01	3.2101800000000000