Year Percent 1991-01-01 0.723783000000000 1992-01-01 0.756268000000000 1993-01-01 1.045240000000000 1994-01-01 4.236110000000000 1995-01-01 4.742640000000000 1996-01-01 7.439120000000000 1997-01-01 9.740089999999999 1998-01-01 13.534900000000000 1999-01-01 12.947100000000000 2000-01-01 14.461100000000000 2001-01-01 13.344500000000000 2002-01-01 16.054400000000000 2003-01-01 20.168500000000000 2004-01-01 17.079900000000000 2005-01-01 14.946600000000000 2006-01-01 17.835600000000000 2007-01-01 19.574400000000000 2008-01-01 16.181800000000000 2009-01-01 22.092700000000000 2010-01-01 22.619100000000000 2011-01-01 22.891100000000000 2012-01-01 14.370300000000000 2013-01-01 11.520700000000000 2014-01-01 14.698900000000000 2015-01-01 15.727300000000000 2016-01-01 12.053500000000000