Year % 1992 14.81 1993 13.87 1995 13.09 1996 14.92 1997 14.93 1998 17.15 1999 15.59 2000 15.61 2001 13.47 2002 15.15 2003 15.22 2004 12.14 2005 10.87 2006 10.94 2007 11.87 2008 11.54 2009 12.09 2010 11.86 2011 11.73 2012 11.53 2013 12.62 2014 13.05 2015 12.93 2016 13.05 2017 13.18 2018 12.91 2019 12.6 2020 12.59 2021 12.31