Year	Number
2004	-0.25019159913063
2005	-0.940376818180084
2006	-1.00624966621399
2007	-1.10214805603027
2008	-1.17250311374664
2009	-1.2189861536026
2010	-1.31824922561646
2011	-1.40494549274445
2012	-1.32609736919403
2013	-1.3505893945694
2014	-0.930841028690338
2015	-0.873311758041382
2016	-0.815027713775635
2017	-0.815004408359528
2018	-0.662966728210449
2019	-0.456636726856232
2020	-0.43056333065033
2021	-0.384524792432785
2022	-0.261825948953629