Year Number 1996 3.72340416908264 1998 2.12765955924988 2000 5.29100513458252 2002 12.6984128952026 2003 9.04522609710693 2004 4.36893224716187 2005 6.31067943572998 2006 7.72946882247925 2007 7.72946882247925 2008 9.13461494445801 2009 7.5829381942749 2010 4.26540279388428 2011 4.7393364906311 2012 5.68720388412476 2013 4.7393364906311 2014 6.1904764175415 2015 6.66666650772095 2016 6.1904764175415 2017 5.2380952835083 2018 6.60377359390259 2019 11.7924528121948 2020 10.3773584365845 2021 10.3773584365845 2022 8.01886749267578