Year % 1992 5.44 1997 4.92 2001 4.9 2002 6.53 2003 4.98 2004 4.88 2005 3.33 2006 3.48 2007 3.37 2008 2.62 2009 2.96 2012 2.25 2013 2.53 2014 2.47 2015 1.79 2016 1.35 2017 1.75 2018 1.75 2019 1.74 2020 1.73 2021 2.04