Year % 2001 13.87 2002 12.95 2003 12.94 2004 11.88 2005 11.97 2006 11.7 2007 11.82 2008 11.82 2009 11.82 2010 11.46 2011 10.91 2012 12.48 2013 12.93 2014 12.7 2015 14.08 2016 14.44 2017 16.07 2018 18.82 2019 19.74 2020 14.44 2021 14.03