Year	Number
1996	-1.31153786182404
1998	-1.19284749031067
2000	-1.14544129371643
2002	-1.30688047409058
2003	-1.48176205158234
2004	-1.55118668079376
2005	-1.43667340278625
2006	-1.34531164169312
2007	-1.59425187110901
2008	-2.01279425621033
2009	-2.32902073860168
2010	-2.4237163066864
2011	-2.42679643630981
2012	-2.43066310882568
2013	-2.37482810020447
2014	-2.66557502746582
2015	-2.66801619529724
2016	-2.78448867797852
2017	-2.93431544303894
2018	-2.9960310459137
2019	-2.77087378501892
2020	-2.64764642715454
2021	-2.58030962944031
2022	-2.47688031196594