Year	Number
1996	-1.58061397075653
1998	-1.53433048725128
2000	-1.42889153957367
2002	-1.71623635292053
2003	-1.7036999464035
2004	-1.7362893819809
2005	-1.73587083816528
2006	-1.53548514842987
2007	-1.54923272132874
2008	-1.54207372665405
2009	-1.53503668308258
2010	-1.5512946844101
2011	-1.43966603279114
2012	-1.35677540302277
2013	-1.24345028400421
2014	-1.19420993328094
2015	-1.2588711977005
2016	-0.900859355926514
2017	-0.95970630645752
2018	-1.04310393333435
2019	-1.07851421833038
2020	-1.1947249174118
2021	-1.46798777580261
2022	-1.52855384349823