Year Percent 1998-01-01 48.750 1999-01-01 5.160 2000-01-01 3.970 2001-01-01 4.290 2002-01-01 3.440 2003-01-01 3.630 2004-01-01 3.420 2005-01-01 3.395 2006-01-01 3.870 2007-01-01 4.050 2008-01-01 3.760 2009-01-01 6.060 2010-01-01 7.220 2011-01-01 6.215 2012-01-01 8.510 2013-01-01 9.470 2014-01-01 9.865 2015-01-01 10.090