Year Percent 1999-01-01 11.050 2000-01-01 10.725 2001-01-01 11.000 2002-01-01 11.100 2003-01-01 12.425 2004-01-01 14.800 2005-01-01 18.100 2006-01-01 20.900 2007-01-01 23.250 2008-01-01 26.400 2009-01-01 28.950 2010-01-01 32.250 2011-01-01 34.575 2012-01-01 38.000 2013-01-01 40.450 2014-01-01 42.150 2015-01-01 45.800 2016-01-01 48.200 2017-01-01 53.050