Year Number 1996 15.7608699798584 1998 16.3043479919434 2000 16.3043479919434 2002 25.4054050445557 2003 21.0810813903809 2004 31.8407955169678 2005 25 2006 36.764705657959 2007 45.6310691833496 2008 50 2009 51.6746406555176 2010 52.1531105041504 2011 52.6066360473633 2012 51.6587677001953 2013 51.6587677001953 2014 50 2015 48.0952377319336 2016 48.5714302062988 2017 48.5714302062988 2018 49.523811340332 2019 49.523811340332 2020 45.238094329834 2021 46.1904754638672 2022 43.8679237365723