Year Number 1996 49.4623641967773 1998 52.9411773681641 2000 54.7872352600098 2002 51.8518524169922 2003 47.6190490722656 2004 47.7832527160645 2005 50.2439041137695 2006 27.8048782348633 2007 30.0970878601074 2008 33.980583190918 2009 33.4928245544434 2010 30 2011 28.4360198974609 2012 31.2796211242676 2013 28.9099521636963 2014 23.5576915740967 2015 29.5238094329834 2016 25.7142848968506 2017 21.4285717010498 2018 17.619047164917 2019 17.1428565979004 2020 18.5714282989502 2021 18.0952377319336 2022 21.2264156341553