Year	Number
1996	-1.60037040710449
1998	-1.75848841667175
2000	-1.83338677883148
2002	-1.8093113899231
2003	-1.76460289955139
2004	-1.78085947036743
2005	-1.93023896217346
2006	-2.07179737091064
2007	-2.11763787269592
2008	-2.10014271736145
2009	-2.10261058807373
2010	-2.08567190170288
2011	-2.12443065643311
2012	-2.0335488319397
2013	-1.96649706363678
2014	-1.91325414180756
2015	-1.95613789558411
2016	-1.88678896427155
2017	-1.79730880260468
2018	-1.62728905677795
2019	-1.65237808227539
2020	-1.53167593479156
2021	-1.39761197566986
2022	-1.33025205135345