Year Number 1996 6.91489362716675 1998 7.44680833816528 2000 5.8201060295105 2002 12.6984128952026 2003 6.03015089035034 2004 4.36893224716187 2005 6.31067943572998 2006 7.24637699127197 2007 3.86473441123962 2008 1.92307686805725 2009 1.89573454856873 2010 3.3175356388092 2011 2.36966824531555 2012 3.79146909713745 2013 3.3175356388092 2014 5.2380952835083 2015 2.85714292526245 2016 2.85714292526245 2017 1.42857146263123 2018 2.35849046707153 2019 2.8301887512207 2020 2.35849046707153 2021 4.24528312683105 2022 4.24528312683105