Year % 2002 14.17 2003 13.8 2004 13.89 2005 13.92 2006 13.87 2007 13.98 2008 13.94 2009 13.93 2012 7.87 2015 7.84 2016 7.84 2017 7.81 2020 7.81 2021 7.81