Year % 2001 5.34931128202376 2002 5.927355718332035 2003 6.7641550950856475 2004 6.6863258088786655 2005 7.125838113621322 2006 5.77130181827702 2007 6.926243001893183 2008 7.956288374844389 2009 8.623417560597476 2010 7.791056527291125 2011 7.621425089915175 2012 7.895374354266334 2013 8.06087311639654 2014 6.670060738506403 2015 6.585216899648773 2016 6.2039703283796195 2017 5.697404354894547 2018 6.087427254102259 2019 6.3479530031872455 2020 6.64571889373233 2021 5.775956728178007 2022 4.913448416032926 2023 5.338403666857587