Year % 1996 21.71 1999 17.7 2000 17.77 2001 11.38 2002 12.12 2003 11.97 2005 11.85 2006 9.3 2007 8.78 2010 12.2 2011 12.18 2012 10.46 2013 11.05 2014 8.03 2015 7.45 2016 7.77 2019 7.5 2020 7.85