Year Number 1996 7.97872352600098 1998 15.957447052002 2000 24.8677253723145 2002 28.0423278808594 2003 28.1407032012939 2004 24.2718448638916 2005 20.8737869262695 2006 17.3913040161133 2007 14.0096616744995 2008 13.4615383148193 2009 14.6919431686401 2010 13.2701425552368 2011 15.6398105621338 2012 17.5355453491211 2013 15.6398105621338 2014 10 2015 10.9523811340332 2016 14.2857141494751 2017 11.4285717010498 2018 13.2075471878052 2019 11.7924528121948 2020 12.7358493804932 2021 13.6792449951172 2022 13.2075471878052