Year Number 1996 60 1998 61.6915435791016 2000 56.2189064025879 2002 53.7313423156738 2003 63.1840782165527 2004 62.5 2005 63.9423065185547 2006 58.6538467407227 2007 57.211540222168 2008 55.288459777832 2009 55.4502372741699 2010 54.028434753418 2011 52.1126747131348 2012 53.521125793457 2013 51.6431922912598 2014 49.7536964416504 2015 50.2463035583496 2016 48.7684745788574 2017 46.305419921875 2018 43.2038841247559 2019 43.961353302002 2020 40.5797119140625 2021 42.512077331543 2022 42.0289840698242