Year Percent 1992-01-01 79.872000000000000 1993-01-01 43.046200000000000 1994-01-01 8.967980000000000 1995-01-01 6.121110000000000 1996-01-01 7.243360000000001 1997-01-01 7.842480000000000 1998-01-01 8.806430000000000 1999-01-01 10.542300000000000 2000-01-01 12.575300000000000 2001-01-01 13.284800000000000 2002-01-01 13.497700000000000 2003-01-01 13.570900000000000 2004-01-01 13.697700000000000 2005-01-01 14.584000000000001 2006-01-01 16.103400000000000 2007-01-01 18.480200000000000 2008-01-01 20.052400000000000 2009-01-01 19.698400000000000 2010-01-01 16.131600000000000 2011-01-01 17.997600000000000 2012-01-01 19.837000000000000 2013-01-01 22.992800000000000 2014-01-01 24.906300000000000 2015-01-01 27.625700000000000 2016-01-01 31.613600000000000