Year	Percent
1999-01-01	2.88098057422565
2000-01-01	4.85546397385474
2001-01-01	4.60638177558343
2002-01-01	4.12331218085686
2003-01-01	4.39281323610736
2004-01-01	3.26147213512787
2005-01-01	2.97324784375360
2006-01-01	2.47760976863322
2007-01-01	3.54676594991573
2008-01-01	2.62663947657441
2009-01-01	2.50629611211112
2010-01-01	1.92557622043717
2011-01-01	2.47923355272668
2012-01-01	2.70999770900464
2013-01-01	3.20253510099920
2014-01-01	2.82251184540988
2015-01-01	3.41761333206818
2016-01-01	3.76677889589646
2017-01-01	3.72300938605443
