Year	Index
1980	8.095
1981	9.584
1982	10.952
1983	11.608
1984	12.705
1985	14.841
1986	20.212
1987	34.649
1988	45.044
1989	51.974
1990	57.749
1991	62.946
1992	69.933
1993	79.165
1994	91.299
1995	98.349
1996	107.074
1997	109.097
1998	108.057
1999	104.058
2000	100
2001	103.401
2002	102.866
2003	108.829
2004	113.653
2005	121.882
2006	134.546
2007	140.839
2008	162.179
2009	166.726
2010	174.059