Year	Number
1996	-1.54957222938538
1998	-1.44287765026093
2000	-1.48983597755432
2002	-1.16489124298096
2003	-1.17799639701843
2004	-1.28100097179413
2005	-0.634234488010406
2006	-0.723143577575684
2007	-0.714045226573944
2008	-0.685290634632111
2009	-0.689463794231415
2010	-0.942692875862122
2011	-0.927631795406342
2012	-0.894518375396729
2013	-0.953051269054413
2014	-1.04256463050842
2015	-1.27204144001007
2016	-1.5554780960083
2017	-1.57584190368652
2018	-1.6694837808609
2019	-1.72377049922943
2020	-1.52686941623688
2021	-1.40298771858215
2022	-1.38799297809601