Year	Number
1996	-1.88991796970367
1998	-1.91843712329865
2000	-2.03981137275696
2002	-2.01282620429993
2003	-2.08195519447327
2004	-2.12265229225159
2005	-2.16620492935181
2006	-2.2332706451416
2007	-2.21349167823792
2008	-2.20797920227051
2009	-2.17256188392639
2010	-2.06740403175354
2011	-1.84963369369507
2012	-1.62011933326721
2013	-1.4616265296936
2014	-1.34398937225342
2015	-1.21897649765015
2016	-0.796729266643524
2017	-0.86463338136673
2018	-0.900316596031189
2019	-0.857177436351776
2020	-0.939285516738892
2021	-1.65794944763184
2022	-1.80904972553253