Year % 1996 17.55 1999 15.51 2000 12.4 2001 13.68 2002 13.8 2003 13.42 2006 11.56 2007 11.46 2008 10.82 2009 13.78 2010 10.06 2011 11.04 2012 11.75 2013 11.74 2014 10.15 2015 10.17 2016 10.2 2017 38.02 2018 38.02 2019 37.99 2020 8.93