Year % 1991 11.88 1993 11.52 1996 6.73 1997 6.84 1998 6.65 1999 6.15 2000 5.93 2001 5.76 2002 4.6 2003 4.71 2004 4.67 2005 3.9 2006 5.16 2007 5.35 2008 5.11 2009 5.07 2010 4.6 2011 3.2 2012 3.32 2013 3.4 2014 3.4 2015 3.22 2016 3.19 2017 3.19 2018 3.22 2019 3.02 2020 3 2021 3.09