Year Number 1996 52.7173919677734 1998 35.8695640563965 2000 40.2173919677734 2002 23.7837829589844 2003 19.4594593048096 2004 22.3880596160889 2005 25.4901962280273 2006 39.2156867980957 2007 38.8349533081055 2008 44.1747589111328 2009 42.1052627563477 2010 39.2344512939453 2011 41.7061614990234 2012 45.497631072998 2013 47.3933639526367 2014 51.9230766296387 2015 48.0952377319336 2016 51.9047622680664 2017 55.7142868041992 2018 52.3809509277344 2019 56.6666679382324 2020 58.0952377319336 2021 60.9523811340332 2022 59.4339637756348