Year	Percent
1991-01-01	53.361400000000000
1992-01-01	51.068000000000005
1993-01-01	21.789200000000000
1994-01-01	13.105800000000000
1995-01-01	14.913800000000000
1996-01-01	17.486300000000000
1997-01-01	18.869800000000000
1998-01-01	19.320800000000000
1999-01-01	17.352000000000000
2000-01-01	18.794000000000000
2001-01-01	21.781400000000000
2002-01-01	24.917400000000000
2003-01-01	27.381600000000000
2004-01-01	31.332200000000000
2005-01-01	36.507600000000000
2006-01-01	39.654500000000000
2007-01-01	43.350500000000000
2008-01-01	47.722100000000000
2009-01-01	52.304200000000000
2010-01-01	41.448400000000000
2011-01-01	33.805300000000000
2012-01-01	36.687500000000000
2013-01-01	39.544000000000004
2014-01-01	40.795000000000000
2015-01-01	38.987700000000000
2016-01-01	36.552700000000000