Year % 1996 21.01 1999 17.19 2000 17.56 2001 12.24 2002 12.24 2003 12.19 2006 1.87 2007 10.22 2010 11.97 2011 11.81 2012 9.71 2013 9.71 2015 9.22 2016 8.71 2017 8.19 2018 7.98 2019 7.78 2020 7.99 2021 8.04