Year % 1990 37.1 1993 45.77 1994 43.88 1997 40.5 1998 20.56 2000 11.18 2001 11.01 2003 8.57 2004 8.12 2005 9.63 2006 8.19 2007 8.54 2008 8.28 2009 9.67 2010 12.01 2011 11.18 2012 9.7 2014 9.57 2015 6.9 2017 15.22 2018 19.46 2019 23.19 2020 11.75 2021 11.03