Year	Number
1996	-1.89035034179688
1998	-1.91686367988586
2000	-1.79194414615631
2002	-1.86447262763977
2003	-1.83121395111084
2004	-1.7434059381485
2005	-1.72836196422577
2006	-1.76751530170441
2007	-2.08427405357361
2008	-2.02107429504395
2009	-1.78495585918427
2010	-1.871253490448
2011	-1.87601327896118
2012	-1.90760576725006
2013	-1.89721143245697
2014	-1.64322245121002
2015	-1.66990995407104
2016	-1.662348985672
2017	-1.70286679267883
2018	-1.60607719421387
2019	-1.4345076084137
2020	-1.49044620990753
2021	-1.58492517471313
2022	-1.46298551559448