Year Percent 1998-01-01 34.27440000000000 1999-01-01 38.34340000000000 2000-01-01 44.90000000000000 2001-01-01 47.90000000000000 2002-01-01 44.79370000000000 2003-01-01 50.87390000000000 2004-01-01 52.74170000000000 2005-01-01 51.22880000000000 2006-01-01 60.80520000000000 2007-01-01 59.44370000000000 2008-01-01 50.38680000000000 2009-01-01 44.48500000000000 2010-01-01 49.66010000000000 2011-01-01 52.28920000000000 2012-01-01 61.35140000000000 2013-01-01 57.15180000000000 2014-01-01 73.69800000000001 2015-01-01 72.58070000000000 2016-01-01 60.24300000000000