Year	Index (Units)
1981	0.101
1982	0.111
1983	0.115
1984	0.144
1985	0.230
1986	0.568
1987	4.781
1988	6.444
1989	8.401
1990	14.877
1991	19.964
1992	41.933
1993	43.865
1994	49.045
1995	54.431
1996	58.048
1997	61.954
1998	65.572
1999	63.804
2000	62.776
2001	62.735
2002	65.078
2003	66.517
2004	67.833
2005	66.747
2006	71.562
2007	75.829
2008	80.587
2009	83.319
2010	87.125
2011	89.843
2012	98.899
2013	100.007
2014	99.300
2015	95.900
2016	98.900
2017	103.900
2018	108.000
2019	115.500
2020	284.000
2021	921.400
2022	2045.500