Year % 1996 12.6 1997 13.21 2000 10.21 2001 10.21 2002 11.29 2008 10.14 2009 10.25 2010 8.61 2011 8.53 2012 8.58 2013 8.44 2014 7.75 2015 7.2 2016 6.26 2017 5.99 2018 6.61 2019 7.61 2020 6.06 2021 6.44