Year	Years
1970	0.7644
1971	0.7493
1972	0.8135
1973	0.6806
1974	0.3533
1975	0.801
1976	0.1639
1977	0.7238
1978	1.295
1979	0.9771
1980	-0.1169
1981	0.7562
1982	0.9458
1983	0.877
1984	1.181
1985	1.246
1986	1.48
1987	1.188
1988	1.238
1989	1.572
1990	2.443
1991	2.237
1992	1.79
1993	2.393
1994	2.283
1995	2.22
1996	2.303
1997	2.658
1998	2.199
1999	2.177
2000	2.499
2001	2.453
2002	2.225
2003	2.018