Year % 1993 4.88 1996 4.82 2001 13.2 2002 13.28 2003 13.3 2004 13.24 2005 13.29 2006 13.14 2007 12.9 2008 12.9 2009 12.82 2010 12.68 2011 12.58 2012 12.62 2013 12.62 2014 12.68 2015 12.14 2016 11.74 2017 12.3 2018 11.93 2019 11.65 2020 11.66 2021 11.66