Year % 1990 10.37 1993 11.93 1995 6.19 1996 5.97 1997 5.16 1998 4.84 1999 4.66 2000 5.28 2001 5.01 2002 5.01 2003 4.87 2004 4.95 2005 5.01 2006 4.92 2007 4.77 2008 4.97 2009 5.13 2010 5.03 2011 5.47 2012 5.47 2013 5.5 2014 5.53 2015 5.5 2016 5.38 2017 5.24 2018 5.04 2019 4.9 2020 4.72 2021 4.55