Year Number 1996 0 1998 0 2000 0.52910053730011 2002 0 2003 5.52763795852661 2004 4.36893224716187 2005 6.31067943572998 2006 13.5265703201294 2007 19.3236713409424 2008 19.7115383148193 2009 16.5876770019531 2010 23.222749710083 2011 27.488151550293 2012 25.1184825897217 2013 28.4360198974609 2014 23.8095245361328 2015 33.3333320617676 2016 30.4761905670166 2017 33.8095245361328 2018 37.2641525268555 2019 33.0188674926758 2020 34.9056587219238 2021 34.9056587219238 2022 31.6037731170654