Year Percent 2000-01-01 0.31 2001-01-01 0.61 2002-01-01 0.98 2003-01-01 1.40 2004-01-01 1.93 2005-01-01 2.38 2006-01-01 2.85 2007-01-01 3.65 2008-01-01 3.16 2009-01-01 4.32 2010-01-01 5.33 2011-01-01 5.66 2012-01-01 6.93 2013-01-01 8.29 2014-01-01 9.76 2015-01-01 10.54 2016-01-01 11.61