Year % 1990 82.13 1992 56.95 1996 37.64 1997 29.04 1999 32.68 2000 33.58 2001 31.62 2002 28.62 2003 25.13 2004 28.26 2005 15.2 2006 12.94 2007 13.3 2008 8.91 2009 9.22 2010 7.78 2011 9.37 2012 9.43 2013 9.3 2015 8.51 2016 7.84 2017 7.8 2018 7.93 2019 8.86 2020 8.18 2021 8.8