Year % 2000 21.89 2001 17.85 2002 17.72 2003 15.73 2004 15.69 2005 16.18 2006 14.67 2007 14.72 2008 14.37 2009 13.62 2010 13.86 2011 13.77 2012 13.5 2013 13.33 2014 13.02 2015 12.77 2016 12.77 2017 13.66 2020 15.29