Year	Number
1996	-1.12732779979706
1998	-1.12412047386169
2000	-1.10480463504791
2002	-1.63767862319946
2003	-1.54904592037201
2004	-1.58287799358368
2005	-1.75138831138611
2006	-2.02467846870422
2007	-2.43270516395569
2008	-2.5730094909668
2009	-2.644526720047
2010	-2.67593312263489
2011	-2.81003546714783
2012	-2.67700362205505
2013	-2.60330200195313
2014	-2.40127921104431
2015	-2.47188353538513
2016	-2.47387385368347
2017	-2.39691042900085
2018	-2.2538845539093
2019	-2.25163745880127
2020	-1.79264628887177
2021	-1.7136561870575
2022	-1.90026199817657