Year	Number
1996	-1.57728278636932
1998	-1.65626657009125
2000	-1.69253444671631
2002	-1.93202567100525
2003	-1.9572502374649
2004	-1.98201262950897
2005	-2.0011305809021
2006	-2.08871555328369
2007	-2.15612840652466
2008	-2.10970687866211
2009	-2.08251118659973
2010	-2.04029369354248
2011	-2.16572093963623
2012	-2.25042843818665
2013	-2.21640849113464
2014	-2.25916385650635
2015	-2.23753476142883
2016	-2.17076778411865
2017	-2.15989255905151
2018	-2.15286207199097
2019	-2.18392252922058
2020	-2.02821326255798
2021	-1.90999531745911
2022	-1.9442834854126