Year	Percent
2000-01-01	28.4660943172965
2001-01-01	27.9844665912390
2002-01-01	28.7860126301631
2003-01-01	28.5028090333041
2004-01-01	29.3063270120549
2005-01-01	27.3218959569706
2006-01-01	25.2656544201940
2007-01-01	23.9710532883881
2008-01-01	21.0901149859783
2009-01-01	20.1757121102054
2010-01-01	19.9532131760901
2011-01-01	20.9749055680158
2012-01-01	21.9173157861474
2013-01-01	22.2408490578863
2014-01-01	24.3986918141097
2015-01-01	25.7299957771946
2016-01-01	25.7833201688154
2017-01-01	26.0541209431113