Year % 2001 5.17 2002 5.39 2004 4.84 2005 5.95 2006 6.12 2007 6.24 2008 5.78 2009 5.45 2010 5 2011 4.76 2012 4.96 2013 5.02 2014 4.34 2015 5.3 2016 5.64 2017 4.52 2018 4.72 2019 11.98 2020 3.99 2021 4.6