Year	Number
1996	-0.347959876060486
1998	-0.0441065803170204
2000	-0.180450946092606
2002	0.277536004781723
2003	0.0636451989412308
2004	-0.285746335983276
2005	-0.461608588695526
2006	-0.278217822313309
2007	-0.339876115322113
2008	-0.339036047458649
2009	-0.509100556373596
2010	-0.805789709091187
2011	-2.01210689544678
2012	-2.68227386474609
2013	-2.68114280700684
2014	-2.74882411956787
2015	-2.965176820755
2016	-2.90603613853455
2017	-2.61291766166687
2018	-2.73627853393555
2019	-2.73033118247986
2020	-2.71175765991211
2021	-2.65949296951294
2022	-2.79725193977356