Year % 1990 25.37 1993 22.91 1994 23.31 1997 19.25 1998 10.02 2000 8.82 2001 8.8 2003 8.89 2004 9.79 2005 11 2006 10.68 2007 10.25 2008 10.14 2009 9.99 2010 8.79 2011 8.79 2012 8.56 2014 8.22 2015 7.29 2017 8.28 2018 8.07 2019 8.07 2020 7.23 2021 4.36