Year	Years
1970	1.958
1971	2.829
1972	3.243
1973	1.374
1974	2.612
1975	1.223
1976	0.7932
1977	1.287
1978	0.218
1979	-0.353
1980	-0.3895
1981	-0.0544
1982	1.089
1983	0.4409
1984	-0.165
1985	-1.145
1986	-0.6268
1987	-1.012
1988	-0.1781
1989	0.5216
1990	0.2744
1991	-0.043
1992	-0.9004
1993	-1.004
1994	-1.117
1995	-1.557
1996	-1.7
1997	-1.477
1998	-0.9595
1999	0.06624
2000	0.4442
2001	0.7903
2002	0.00819
2003	0.729