Year Percent 2000-01-01 1.15 2001-01-01 1.23 2002-01-01 1.29 2003-01-01 1.29 2004-01-01 1.29 2005-01-01 1.46 2006-01-01 1.72 2007-01-01 1.96 2008-01-01 2.13 2009-01-01 2.31 2010-01-01 2.48 2011-01-01 2.62 2012-01-01 2.69 2013-01-01 2.75 2014-01-01 2.77 2015-01-01 2.45