Year Number 1996 34.042552947998 1998 25 2000 25.9259262084961 2002 37.5661392211914 2003 51.7587928771973 2004 40.7766990661621 2005 42.7184448242188 2006 38.164249420166 2007 47.8260879516602 2008 44.230770111084 2009 52.6066360473633 2010 49.7630348205566 2011 44.0758285522461 2012 51.1848335266113 2013 50.2369651794434 2014 35.7142868041992 2015 37.1428565979004 2016 22.380952835083 2017 25.238094329834 2018 29.7169818878174 2019 30.1886787414551 2020 20.2830181121826 2021 18.8679237365723 2022 17.9245281219482