Year Number 1996 9.54773902893066 1998 12.5 2000 13.4328355789185 2002 4.47761201858521 2003 4.97512435913086 2004 6.25 2005 7.65550231933594 2006 14.3540668487549 2007 13.3971290588379 2008 14.9038457870483 2009 12.3222751617432 2010 11.3744077682495 2011 11.7370891571045 2012 11.2676057815552 2013 12.6760559082031 2014 12.5 2015 14.7619047164917 2016 14.7619047164917 2017 19.0476188659668 2018 18.5714282989502 2019 18.5714282989502 2020 20.9523811340332 2021 20.9523811340332 2022 19.8113212585449