Year % 1990 36.43 1993 33.24 1994 33.69 1997 27.82 1998 19.9 2000 16.48 2001 16.2 2003 15.07 2004 16.79 2005 18.01 2006 17.77 2007 17.62 2008 17.46 2009 17.41 2010 17.93 2011 17.83 2012 18.31 2014 16.27 2015 13.29 2017 19.77 2018 25.36 2019 38.25 2020 18.15 2021 13.22