Year	Index
1981	0.02
1982	0.041
1983	0.101
1984	0.122
1985	0.304
1986	0.751
1987	2.558
1988	7.632
1989	13.519
1990	17.152
1991	22.696
1992	37.746
1993	36.857
1994	39.679
1995	44.227
1996	46.63
1997	51.495
1998	51.031
1999	55.346
2000	57.68
2001	55.128
2002	58.282
2003	61.725
2004	66.665
2005	69.114
2006	76.636
2007	80.608
2008	92.082
2009	102.153
2010	103.641
2011	128.153
2012	133.619
2013	140.905
2014	143.802
2015	155.862
2016	164.726
2017	170.166
2018	173.96
2019	181.005
2020	189.683
2021	199.062
2022	209.015
2023	219.466
2024	230.439