Year Number 1996 11.702127456665 1998 13.8297872543335 2000 15.3439149856567 2002 4.7619047164917 2003 8.04020118713379 2004 8.73786449432373 2005 9.70873832702637 2006 5.31400966644287 2007 5.79710149765015 2008 6.25 2009 4.7393364906311 2010 3.79146909713745 2011 5.21327018737793 2012 5.21327018737793 2013 3.3175356388092 2014 0.476190477609634 2015 6.66666650772095 2016 7.14285707473755 2017 5.2380952835083 2018 3.77358484268188 2019 4.24528312683105 2020 2.8301887512207 2021 4.24528312683105 2022 4.24528312683105