Year Number 2004 28.3582096099854 2005 23.529411315918 2006 9.80392169952393 2007 6.7961163520813 2008 2.42718458175659 2009 4.78468894958496 2010 2.87081336975098 2011 2.36966824531555 2012 2.36966824531555 2013 1.89573454856873 2014 5.76923084259033 2015 10.4761905670166 2016 11.9047622680664 2017 8.09523773193359 2018 11.9047622680664 2019 13.3333330154419 2020 14.7619047164917 2021 18.0952377319336 2022 25