Year	Number
1996	-1.29170477390289
1998	-1.17601227760315
2000	-1.27172422409058
2002	-1.25113701820374
2003	-1.34417974948883
2004	-1.35064733028412
2005	-1.44725239276886
2006	-1.44629228115082
2007	-1.61325109004974
2008	-1.67209553718567
2009	-1.55229878425598
2010	-1.64539110660553
2011	-1.60047078132629
2012	-1.43037283420563
2013	-1.44590842723846
2014	-1.36474287509918
2015	-1.35423982143402
2016	-1.54035270214081
2017	-1.53190970420837
2018	-1.50288057327271
2019	-1.41949915885925
2020	-1.49369978904724
2021	-1.15232741832733
2022	-1.18377649784088