Year Number 1996 22.8723411560059 1998 25.5319156646729 2000 27.5132274627686 2002 21.6931209564209 2003 20.1005020141602 2004 16.019416809082 2005 19.4174766540527 2006 18.3574886322021 2007 13.043478012085 2008 9.13461494445801 2009 4.26540279388428 2010 3.79146909713745 2011 2.36966824531555 2012 2.84360194206238 2013 4.26540279388428 2014 4.2857141494751 2015 2.38095235824585 2016 1.42857146263123 2017 0.952380955219269 2018 0.943396210670471 2019 2.8301887512207 2020 2.35849046707153 2021 3.30188679695129 2022 4.24528312683105