Year Number 1996 15.5778894424438 1998 8 2000 23.8805961608887 2002 32.3383102416992 2003 25.3731346130371 2004 21.634614944458 2005 21.0526313781738 2006 20.0956935882568 2007 15.7894735336304 2008 12.9807691574097 2009 15.1658763885498 2010 14.2180099487305 2011 15.4929580688477 2012 8.45070457458496 2013 6.57277011871338 2014 12.9807691574097 2015 13.3333330154419 2016 10.4761905670166 2017 11.9047622680664 2018 18.5714282989502 2019 18.0952377319336 2020 16.1904754638672 2021 14.2857141494751 2022 13.2075471878052