Year % 1998 10.6 1999 12.1 2000 11.1 2001 10.3 2002 9.7 2003 9.3 2004 7.5 2005 8.9 2006 9.3 2007 8.7 2008 8.5 2009 7.9 2010 8.5 2011 8.2 2012 7 2013 6.6 2014 6.8 2015 6.2 2016 5.9 2017 5.2 2018 5.2 2019 5.5 2020 3.9