Year % 1992 36.02 1993 33.32 1994 31.8 1996 26.14 1997 18.43 1998 18.36 1999 18.16 2000 18.87 2001 17.81 2002 13.66 2003 12.53 2004 11.69 2005 10.72 2006 11.1 2007 11.2 2008 10.96 2009 10.96 2010 11 2011 10.95 2014 10.41 2015 10.44 2016 10.76 2017 10.82 2018 10.82 2019 9.24 2020 9.25 2021 9.26