Year Number 1996 16.3043479919434 1998 10.8695650100708 2000 7.60869550704956 2002 11.8918914794922 2003 16.7567558288574 2004 12.4378108978271 2005 14.7058820724487 2006 10.7843141555786 2007 9.22330093383789 2008 8.73786449432373 2009 12.4401912689209 2010 11.4832534790039 2011 8.53080558776855 2012 11.3744077682495 2013 9.47867298126221 2014 10.0961542129517 2015 11.4285717010498 2016 10.9523811340332 2017 10.4761905670166 2018 13.3333330154419 2019 11.9047622680664 2020 14.7619047164917 2021 17.1428565979004 2022 20.2830181121826