Year Number 1996 37.2340431213379 1998 40.957447052002 2000 48.6772499084473 2002 33.3333320617676 2003 45.7286415100098 2004 42.2330093383789 2005 43.2038841247559 2006 50.7246360778809 2007 54.5893707275391 2008 49.038459777832 2009 45.971565246582 2010 41.2322273254395 2011 28.9099521636963 2012 27.014217376709 2013 21.8009471893311 2014 20 2015 25.238094329834 2016 16.6666660308838 2017 15.2380952835083 2018 13.2075471878052 2019 11.7924528121948 2020 9.43396186828613 2021 7.54716968536377 2022 8.01886749267578