Year	Number
1996	-1.28972291946411
1998	-1.18912124633789
2000	-1.16092002391815
2002	-1.4958997964859
2003	-1.51251006126404
2004	-1.4396630525589
2005	-1.35421597957611
2006	-1.07539594173431
2007	-1.06105268001556
2008	-1.03830480575562
2009	-1.15610778331757
2010	-1.1588362455368
2011	-1.1788387298584
2012	-1.13882875442505
2013	-1.12007391452789
2014	-1.05556893348694
2015	-0.982365071773529
2016	-1.03762006759644
2017	-0.889033138751984
2018	-0.917747616767883
2019	-0.938902914524078
2020	-0.842660069465637
2021	-0.870013236999512
2022	-0.913734316825867