Year % 1995 6.92 1997 7.72 2002 7.29 2006 4.74 2007 4.73 2008 4.77 2009 4.09 2010 4.06 2011 3.99 2012 4 2013 4.09 2014 4.07 2015 4.07 2016 4.07 2017 4.07 2018 4.07 2019 4.07 2020 4.07 2021 4.07