Year Percent 2001-01-01 85.68230000000000 2002-01-01 83.81920000000000 2003-01-01 78.52700000000000 2004-01-01 78.19390000000000 2005-01-01 74.89020000000000 2006-01-01 60.59120000000000 2007-01-01 64.54950000000000 2008-01-01 65.91850000000000 2009-01-01 72.18950000000000 2010-01-01 76.73560000000000 2011-01-01 74.69170000000000 2012-01-01 75.54550000000000 2013-01-01 78.56550000000000 2014-01-01 79.76400000000000 2015-01-01 84.88600000000001 2016-01-01 80.74120000000000