Year	Index (Units)
1980	47.509
1981	46.819
1982	46.186
1983	41.762
1984	42.652
1985	47.778
1986	34.006
1987	33.793
1988	29.087
1989	28.465
1990	28.063
1991	29.957
1992	31.613
1993	36.206
1994	41.876
1995	44.479
1996	45.753
1997	49.281
1998	48.543
1999	36.614
2000	33.611
2001	42.551
2002	47.438
2003	52.774
2004	56.146
2005	60.965
2006	66.279
2007	70.961
2008	81.672
2009	79.410
2010	86.568
2011	92.487
2012	97.115
2013	99.704
2014	101.751
2015	96.180
2016	97.306
2017	98.213
2018	100.000
2019	99.943
2020	98.119
2021	100.129
2022	102.328
2023	103.122
2024	104.254
2025	105.772
2026	107.312
2027	108.875
2028	110.461
2029	112.070