Year	Number
1996	-1.28434658050537
1998	-1.24869453907013
2000	-1.30290651321411
2002	-1.02666258811951
2003	-1.43155789375305
2004	-1.38584494590759
2005	-1.28446447849274
2006	-1.4435168504715
2007	-1.5439600944519
2008	-1.51846635341644
2009	-1.28908085823059
2010	-1.28319656848907
2011	-1.31766355037689
2012	-1.28702855110168
2013	-1.29103326797485
2014	-1.30408978462219
2015	-1.27286577224731
2016	-1.46149015426636
2017	-1.50140011310577
2018	-1.5878449678421
2019	-1.609050989151
2020	-1.70310807228088
2021	-1.62223398685455
2022	-1.60609889030457