Year Number 1996 14.8936166763306 1998 10.638298034668 2000 4.7619047164917 2002 1.58730161190033 2003 6.03015089035034 2004 5.33980560302734 2005 5.33980560302734 2006 11.5942029953003 2007 9.17874431610107 2008 9.13461494445801 2009 7.5829381942749 2010 9.00473976135254 2011 10.4265403747559 2012 14.6919431686401 2013 17.0616111755371 2014 13.3333330154419 2015 17.1428565979004 2016 14.7619047164917 2017 13.3333330154419 2018 12.7358493804932 2019 10.8490562438965 2020 10.3773584365845 2021 10.3773584365845 2022 11.7924528121948