Year Measure 2000 0.3 2001 0.303 2002 0.284 2003 0.301 2004 0.306 2005 0.303 2006 0.306 2007 0.338 2008 0.343 2009 0.36 2010 0.37 2011 0.381 2012 0.387 2013 0.39 2014 0.394 2015 0.396