Year % 1993 17.89 1995 16.23 1997 13.1 1998 13.03 1999 12.98 2000 12.97 2001 11.79 2002 10.11 2003 9.44 2004 9.65 2005 9.06 2006 8.5 2007 8.43 2008 4.6 2009 4.62 2010 4.82 2011 3.22 2013 2.96 2014 2.89 2015 2.89 2017 1.45 2018 1.32 2019 1.34 2020 1.2 2021 1.14