Year Percent 1995-01-01 44.1691749925000 1996-01-01 44.5024561025000 1997-01-01 44.3460417425000 1998-01-01 44.6969776325000 1999-01-01 45.7230933700000 2000-01-01 46.8229368475000 2001-01-01 46.5016869950000 2002-01-01 46.3252616625000 2003-01-01 46.6995165000000 2004-01-01 47.1516798775000 2005-01-01 48.6165825475000 2006-01-01 49.3937215950000 2007-01-01 50.6503074675000 2008-01-01 51.7119535350000 2009-01-01 52.1590395975000 2010-01-01 53.1812648350000 2011-01-01 53.7036599325000 2012-01-01 58.3333333333333 2013-01-01 58.9916666666667 2014-01-01 60.1833333333333 2015-01-01 60.3833333333333 2016-01-01 61.0500000000000 2017-01-01 61.2416666666667