Year % 2001 9.73089413606573 2002 10.10761896944038 2003 9.926830930191016 2004 9.259214663121869 2005 7.917284549065351 2006 7.970961159056461 2007 9.010579854559982 2008 7.594142952474926 2009 7.753107958112733 2010 8.567175410122488 2011 11.041967710354385 2012 10.979143661547058 2013 12.378650247782485 2014 13.370740969896097 2015 15.848488714287413 2016 17.37476034321878 2017 16.074398204225208 2018 16.96174640196911 2019 19.165118025909667 2020 19.002083148657036 2021 20.220210964969397 2022 21.09615251505473 2023 20.778729409550017