Year	Number
1996	-1.87656342983246
1998	-1.91839897632599
2000	-1.82056438922882
2002	-1.76772034168243
2003	-1.85025274753571
2004	-1.7184351682663
2005	-1.54452848434448
2006	-1.62169671058655
2007	-1.6147369146347
2008	-1.57367646694183
2009	-1.64403963088989
2010	-1.62714993953705
2011	-1.62553715705872
2012	-1.66291427612305
2013	-1.58483183383942
2014	-1.4627605676651
2015	-1.60007810592651
2016	-1.64749825000763
2017	-1.71502315998077
2018	-1.80321037769318
2019	-1.81420874595642
2020	-1.82221555709839
2021	-1.72392868995667
2022	-1.67243385314941