Year	Percent
1991-01-01	10.6330003738403
1992-01-01	11.9099998474121
1993-01-01	11.5299997329712
1994-01-01	11.6859998703003
1995-01-01	11.4300003051758
1996-01-01	12.6199998855591
1997-01-01	14.4399995803833
1998-01-01	17.2500000000000
1999-01-01	18.2900009155273
2000-01-01	18.6879997253418
2001-01-01	17.8999996185303
2002-01-01	18.0200004577637
2003-01-01	19.0400009155273
2004-01-01	18.0699996948242
2005-01-01	17.1749992370605
2006-01-01	17.7600002288818
2007-01-01	16.7999992370605
2008-01-01	16.1130008697510
2009-01-01	17.8199996948242
2010-01-01	16.2679996490479
2011-01-01	15.3400001525879
2012-01-01	16.1200008392334
2013-01-01	15.9600000381470
2014-01-01	15.8299999237061
2015-01-01	19.9099998474121
2016-01-01	27.2500000000000
2017-01-01	30.2099990844727
