Year Percent 1995-01-01 47.6591114925000 1996-01-01 46.8640565825000 1997-01-01 45.5174219775000 1998-01-01 45.1594251975000 1999-01-01 45.9306531600000 2000-01-01 46.6530290675000 2001-01-01 48.3574283575000 2002-01-01 49.1378784175000 2003-01-01 50.3947382875000 2004-01-01 51.5290299875000 2005-01-01 52.3983840200000 2006-01-01 54.8415330350000 2007-01-01 57.1563871100000 2008-01-01 58.4292181400000 2009-01-01 58.7815668350000 2010-01-01 59.8081856450000 2011-01-01 61.2546368700000 2012-01-01 63.1083333333333 2013-01-01 64.6333333333333 2014-01-01 65.1333333333334 2015-01-01 66.2416666666666 2016-01-01 66.5416666666667 2017-01-01 66.7500000000000