Year	Number
1996	-0.611550152301788
1998	-0.789812207221985
2000	-1.08538794517517
2002	-1.36336076259613
2003	-1.43119192123413
2004	-1.55357718467712
2005	-1.67494142055511
2006	-1.53924381732941
2007	-1.57152092456818
2008	-1.54903090000153
2009	-1.53921008110046
2010	-1.47518157958984
2011	-1.46376252174377
2012	-1.47196817398071
2013	-1.38621962070465
2014	-1.25688946247101
2015	-1.16608715057373
2016	-1.17845976352692
2017	-1.1959046125412
2018	-1.13679790496826
2019	-1.16366899013519
2020	-1.11340796947479
2021	-1.13582968711853
2022	-1.10220551490784