Year Number 1996 9.57446765899658 1998 10.638298034668 2000 17.4603176116943 2002 20.1058197021484 2003 20.6030158996582 2004 13.5922327041626 2005 7.76699018478394 2006 0.966183602809906 2007 0.483091801404953 2008 1.92307686805725 2009 4.26540279388428 2010 3.3175356388092 2011 3.3175356388092 2012 3.79146909713745 2013 3.79146909713745 2014 5.7142858505249 2015 4.7619047164917 2016 5.7142858505249 2017 5.2380952835083 2018 5.18867921829224 2019 4.24528312683105 2020 4.24528312683105 2021 5.18867921829224 2022 6.60377359390259