Year	Index (Units)
1980	0.420
1981	0.442
1982	0.443
1983	0.508
1984	0.591
1985	0.697
1986	0.794
1987	1.678
1988	2.078
1989	5.971
1990	9.403
1991	21.835
1992	24.504
1993	28.006
1994	33.039
1995	36.570
1996	37.595
1997	38.107
1998	38.752
1999	44.128
2000	46.115
2001	46.525
2002	48.418
2003	50.729
2004	53.156
2005	56.462
2006	59.658
2007	66.001
2008	72.946
2009	73.719
2010	78.482
2011	85.905
2012	100.000
2013	99.463
2014	97.369
2015	100.295
2016	101.195
2017	103.330
2018	100.346
2019	103.317
2020	76.149
2021	88.817
2022	103.786
2023	91.595
2024	84.974
2025	80.049
2026	78.186
2027	66.848
2028	61.120
2029	56.770