Year	Number
1996	-0.624154627323151
1998	-0.797985851764679
2000	-0.81583034992218
2002	-0.891898393630981
2003	-0.863626658916473
2004	-0.973159849643707
2005	-0.917643487453461
2006	-0.920007109642029
2007	-0.886139214038849
2008	-0.894583106040955
2009	-1.08320450782776
2010	-1.03183209896088
2011	-1.15728986263275
2012	-1.28172242641449
2013	-1.227778673172
2014	-1.43440473079681
2015	-1.71240794658661
2016	-1.9058792591095
2017	-1.95266675949097
2018	-2.27373719215393
2019	-2.32937264442444
2020	-2.36192989349365
2021	-2.3245210647583
2022	-2.23254156112671