Year Number 1996 0.48545891046524 1998 0.187779128551483 2000 0.209914907813072 2002 0.486781418323517 2003 0.598321139812469 2004 0.574418246746063 2005 0.529817044734955 2006 0.654658257961273 2007 0.42527824640274 2008 0.521047174930573 2009 0.619090795516968 2010 0.722773253917694 2011 0.689273953437805 2012 0.828348100185394 2013 0.879969239234924 2014 0.951694786548615 2015 1.05424880981445 2016 0.966515302658081 2017 0.865767598152161 2018 1.00042855739594 2019 1.06583380699158 2020 0.838279902935028 2021 0.834164917469025 2022 0.691895127296448