Year	Percent
2005-01-01	19.7363075823345
2006-01-01	18.3070165468692
2007-01-01	17.8418235605101
2008-01-01	19.7251688781015
2009-01-01	22.5996244669156
2010-01-01	18.5426349751339
2011-01-01	17.5424343547476
2012-01-01	16.2560509444036
2013-01-01	16.0468802165205
2014-01-01	16.4432808180203
2015-01-01	15.5043780380160
2016-01-01	15.6644926962551
2017-01-01	16.8522735932784