Year	Percent
1999-01-01	16.6815
2000-01-01	15.9771
2001-01-01	14.8061
2002-01-01	12.1684
2003-01-01	15.9809
2004-01-01	17.2975
2005-01-01	17.5964
2006-01-01	20.1495
2007-01-01	22.3217
2008-01-01	14.4880
2009-01-01	20.2354
2010-01-01	23.6947
2011-01-01	24.7578
2012-01-01	28.1355
2013-01-01	35.1352
2014-01-01	38.1149
2015-01-01	34.2651
2016-01-01	35.2437