Year Number 1996 34.042552947998 1998 25 2000 30.1587295532227 2002 23.8095245361328 2003 19.0954780578613 2004 20.8737869262695 2005 28.1553401947021 2006 26.0869560241699 2007 21.2560386657715 2008 22.115385055542 2009 17.5355453491211 2010 19.4312801361084 2011 19.4312801361084 2012 18.4834117889404 2013 19.4312801361084 2014 23.3333339691162 2015 23.8095245361328 2016 24.2857151031494 2017 30 2018 23.5849056243896 2019 28.301887512207 2020 26.8867931365967 2021 33.9622650146484 2022 39.1509437561035