Year % 1984 12.1 1987 12.6 1990 12.4 1993 12.2 1996 11.6 1998 12.5 1999 12.6 2000 13.2 2001 13 2002 12.3 2003 12.2 2004 12.1 2005 12 2006 11.8 2007 11.3 2008 11.4 2009 11.5 2010 10.9 2011 10.2 2012 10.2 2013 10.1 2014 10.2 2015 10.4 2016 10.4 2017 10.6 2018 10.7 2019 10.9 2020 10.9 2021 10.9 2022 11 2023 11