Year % 2005 4.07 2006 4.33 2007 4.27 2008 4.49 2009 4.81 2010 4.3 2011 4.36 2012 4.73 2013 5.45 2014 5.61 2015 5.94 2016 5.98 2017 6.33 2018 6.47 2019 6.31 2020 5.93 2021 5.94