Year Number 1996 56.2814064025879 1998 53.5 2000 47.2636833190918 2002 52.7363166809082 2003 55.7213935852051 2004 52.4038467407227 2005 52.1531105041504 2006 53.5885162353516 2007 55.5023918151855 2008 56.25 2009 55.9241714477539 2010 60.1895751953125 2011 57.2769966125488 2012 58.6854476928711 2013 56.8075103759766 2014 62.019229888916 2015 59.0476188659668 2016 61.4285697937012 2017 56.1904754638672 2018 57.6190490722656 2019 57.1428565979004 2020 58.0952377319336 2021 57.1428565979004 2022 58.0188674926758