Year Number 1996 60.7526893615723 1998 50.2673797607422 2000 28.7234039306641 2002 23.8095245361328 2003 21.1640205383301 2004 17.7339897155762 2005 15.6097564697266 2006 10.2439022064209 2007 10.6796112060547 2008 12.62135887146 2009 11.9617223739624 2010 12.380952835083 2011 10.9004735946655 2012 10.9004735946655 2013 9.95260620117188 2014 9.61538505554199 2015 11.9047622680664 2016 12.8571424484253 2017 12.380952835083 2018 13.8095235824585 2019 14.2857141494751 2020 16.1904754638672 2021 17.619047164917 2022 17.9245281219482