Year % 1993 19.96 1997 11.86 2001 12.01 2002 8.76 2003 10.69 2004 10.67 2005 9.98 2006 10.31 2007 9.93 2008 9.7 2009 9.19 2010 8.85 2011 9.21 2012 9.05 2013 8.64 2015 8.17 2016 19.87 2018 8.7 2020 9.3 2021 9.29