Year % 1994 31.75 1996 25.94 1997 27.02 1998 19.9 2000 15.61 2001 13 2003 15.41 2006 12.9 2008 12.02 2009 12.51 2010 11.4 2011 12.07 2012 11.24 2013 8.81 2014 9.08 2015 9.06 2016 9.05 2019 6.83 2020 9.18 2021 9.2