Year Number 1996 23.9130439758301 1998 27.1739139556885 2000 33.6956520080566 2002 40.5405387878418 2003 45.4054069519043 2004 44.2786064147949 2005 43.6274528503418 2006 49.0196075439453 2007 50 2008 51.9417457580566 2009 52.1531105041504 2010 48.3253593444824 2011 50.7108993530273 2012 46.445499420166 2013 47.8672981262207 2014 53.3653831481934 2015 51.4285697937012 2016 50.9523811340332 2017 52.3809509277344 2018 57.1428565979004 2019 60.476188659668 2020 54.761905670166 2021 63.3333320617676 2022 61.3207550048828