Year % 2004 11.2 2005 11.7 2006 12.1 2007 12.3 2008 12.4 2009 12.4 2010 12.5 2011 12.4 2012 12.5 2013 12.4 2014 12.6 2015 12.8 2016 13 2017 13.4 2018 13.3 2019 13.7 2020 13.8 2021 13.8