Year Number 1996 40 1998 41.7910461425781 2000 38.8059692382813 2002 37.8109436035156 2003 35.8208961486816 2004 37.980770111084 2005 38.9423065185547 2006 41.8269233703613 2007 34.1346168518066 2008 28.8461532592773 2009 29.3838863372803 2010 29.8578205108643 2011 26.7605628967285 2012 27.2300472259521 2013 27.6995296478271 2014 29.0640392303467 2015 27.0935955047607 2016 23.645320892334 2017 24.630542755127 2018 29.6116504669189 2019 25.1207733154297 2020 23.6714973449707 2021 24.6376819610596 2022 27.0531406402588