Year % 1996 20.55 1999 17.3 2000 8.27 2001 8.3 2002 8.7 2003 8.81 2004 8.7 2006 8.34 2007 8.46 2010 7.69 2011 7.63 2012 10.52 2013 10.32 2015 8.64 2016 9.17 2020 8.14 2021 8.11