Year Number 1996 35 1998 32.8358192443848 2000 30.8457717895508 2002 22.3880596160889 2003 24.8756217956543 2004 25.9615383148193 2005 25 2006 19.230770111084 2007 19.7115383148193 2008 18.269229888916 2009 20.3791465759277 2010 18.9573459625244 2011 20.1877937316895 2012 29.1079807281494 2013 23.9436626434326 2014 21.1822662353516 2015 21.1822662353516 2016 22.1674880981445 2017 19.7044334411621 2018 17.9611644744873 2019 14.0096616744995 2020 14.0096616744995 2021 13.043478012085 2022 14.4927539825439