Year % 2004 10.6 2005 8.7 2006 8.1 2007 7.9 2008 8.2 2009 9.6 2010 9.8 2011 9.9 2012 10.1 2013 10.6 2014 10.9 2015 10.6 2016 9.2 2017 8.6 2018 9.3 2019 8.8 2020 10.2 2021 9.9