Year	Percent
1995-01-01	24.2802674388603
1996-01-01	23.9792341339524
1997-01-01	23.1111138891444
1998-01-01	22.4466241500100
1999-01-01	21.8025490574856
2000-01-01	21.5202992467368
2001-01-01	20.9303318331657
2002-01-01	19.6324987532083
2003-01-01	18.8700354926311
2004-01-01	18.4815266874966
2005-01-01	18.8984560447001
2006-01-01	18.7586171371069
2007-01-01	17.9037652834024
2008-01-01	18.0934371680490
2009-01-01	17.8742456400219
2010-01-01	17.6597941355920
2011-01-01	17.8350414055821
2012-01-01	17.5364927932098
2013-01-01	17.2826533408483
2014-01-01	18.0906122178522
2015-01-01	18.0029572329683
2016-01-01	17.8222120077879
2017-01-01	17.0637300378287