Year % 2004 9.8 2005 9.9 2006 10 2007 10 2008 10.2 2009 9.8 2010 9.7 2011 9.7 2012 9.4 2013 9.2 2014 9.4 2015 9.6 2016 9.7 2017 10 2018 10.1 2019 10.1 2020 10.3 2021 10.2