Year	Index (Units)
1981	2.356
1982	2.470
1983	2.748
1984	2.898
1985	3.402
1986	3.016
1987	2.891
1988	3.141
1989	3.482
1990	4.391
1991	4.996
1992	5.754
1993	7.347
1994	10.431
1995	12.329
1996	14.427
1997	15.966
1998	16.634
1999	17.191
2000	18.896
2001	21.307
2002	23.065
2003	30.776
2004	36.085
2005	41.420
2006	45.377
2007	47.949
2008	57.106
2009	55.577
2010	57.941
2011	62.264
2012	65.206
2013	68.014
2014	70.725
2015	76.693
2016	84.875
2017	94.070
2018	106.539
2019	127.500
2020	159.600
2021	180.447
2022	250.200
2023	329.860
2024	402.721
2025	456.725
2026	511.600
2027	564.605
2028	609.774
2029	655.507