Year % 2004 5.7 2005 6.4 2006 6.8 2007 7.2 2008 7.3 2009 7.3 2010 7.3 2011 7.3 2012 7.2 2013 7.2 2014 7.2 2015 7.4 2016 8 2017 8.3 2018 8.2 2019 8.6 2020 8.6 2021 8.6