Year Number 1996 3 1998 2.48756217956543 2000 2.98507452011108 2002 1.49253726005554 2003 1.99004971981049 2004 3.36538457870483 2005 3.8461537361145 2006 2.4038462638855 2007 2.4038462638855 2008 3.36538457870483 2009 2.84360194206238 2010 2.84360194206238 2011 3.28638505935669 2012 3.28638505935669 2013 3.28638505935669 2014 3.44827580451965 2015 2.95566511154175 2016 3.94088673591614 2017 4.92610836029053 2018 5.33980560302734 2019 2.89855074882507 2020 1.44927537441254 2021 1.44927537441254 2022 1.44927537441254