Year Number 1996 31.6939888000488 1998 30.0546455383301 2000 32.7868843078613 2002 29.7297306060791 2003 32.4324340820313 2004 35.8208961486816 2005 39.2156867980957 2006 41.9512176513672 2007 38.3495140075684 2008 40.2912635803223 2009 44.4976081848145 2010 38.7559814453125 2011 42.1800956726074 2012 40.7582931518555 2013 51.1848335266113 2014 57.211540222168 2015 56.6666679382324 2016 60.476188659668 2017 59.523811340332 2018 60.476188659668 2019 62.3809509277344 2020 61.9047622680664 2021 70.9523773193359 2022 65.5660400390625