Year Number 1996 1.63934421539307 1998 3.82513666152954 2000 3.27868843078613 2002 1.08108103275299 2003 3.78378367424011 2004 6.46766185760498 2005 7.84313726425171 2006 5.85365867614746 2007 12.1359224319458 2008 21.8446598052979 2009 24.4019145965576 2010 28.2296657562256 2011 27.488151550293 2012 28.9099521636963 2013 28.9099521636963 2014 25 2015 21.4285717010498 2016 19.5238094329834 2017 19.0476188659668 2018 17.619047164917 2019 15.2380952835083 2020 17.1428565979004 2021 17.619047164917 2022 20.7547168731689