Year Number 1996 33.3333320617676 1998 22.9946517944336 2000 16.4893608093262 2002 22.7513236999512 2003 29.6296291351318 2004 29.0640392303467 2005 40.9756088256836 2006 35.1219520568848 2007 33.009708404541 2008 33.4951438903809 2009 30.6220092773438 2010 34.761905670166 2011 34.5971565246582 2012 36.0189590454102 2013 39.3364944458008 2014 31.25 2015 30.4761905670166 2016 30 2017 31.9047622680664 2018 28.5714282989502 2019 28.0952377319336 2020 27.619047164917 2021 29.5238094329834 2022 28.301887512207