Year Number 1996 0.576565086841583 1998 0.701060175895691 2000 0.935157179832459 2002 0.908920228481293 2003 0.947880446910858 2004 1.14497804641724 2005 1.33629047870636 2006 1.1909122467041 2007 1.10401487350464 2008 1.13101947307587 2009 0.965701699256897 2010 0.935810565948486 2011 0.948596119880676 2012 1.0062894821167 2013 0.922868311405182 2014 1.15322852134705 2015 1.03520536422729 2016 0.73615837097168 2017 0.818202197551727 2018 0.776450574398041 2019 -0.228379547595978 2020 0.0566768497228622 2021 0.263209611177444 2022 0.61155503988266