Year	Number
1996	-0.814238488674164
1998	-0.774310111999512
2000	-1.38190841674805
2002	-1.59631824493408
2003	-1.60702157020569
2004	-1.68889737129211
2005	-1.83490836620331
2006	-1.75168538093567
2007	-1.80864059925079
2008	-1.79150533676147
2009	-1.87002050876617
2010	-1.83763182163239
2011	-1.79394936561584
2012	-1.63018405437469
2013	-1.58726119995117
2014	-1.44146907329559
2015	-1.33847284317017
2016	-1.39066338539124
2017	-1.39620387554169
2018	-1.2924633026123
2019	-1.30351531505585
2020	-1.32961118221283
2021	-1.27720153331757
2022	-1.23628377914429