Year Number 1996 9.04255294799805 1998 10.1063833236694 2000 1.58730161190033 2002 7.40740728378296 2003 4.52261304855347 2004 3.88349509239197 2005 0.485436886548996 2006 0.966183602809906 2007 7.24637699127197 2008 8.65384578704834 2009 9.95260620117188 2010 13.2701425552368 2011 16.1137447357178 2012 18.9573459625244 2013 18.0094795227051 2014 24.2857151031494 2015 21.9047622680664 2016 23.3333339691162 2017 25.238094329834 2018 22.6415100097656 2019 22.6415100097656 2020 18.3962268829346 2021 23.5849056243896 2022 24.056604385376