Year	Years
1960	3.192
1961	2.532
1962	2.538
1963	3.474
1964	3.664
1965	3.357
1966	3.227
1967	2.989
1968	3.31
1969	3.515
1970	3.292
1971	3.462
1972	3.867
1973	3.755
1974	3.057
1975	3.167
1976	3.021
1977	2.782
1978	2.782
1979	3.279
1980	3.492
1981	3.943
1982	3.136
1983	1.986
1984	1.85
1985	1.622
1986	0.9033
1987	0.7953
1988	0.141
1989	-0.2287
1990	-0.4589
1991	-0.8008
1992	-0.3536
1993	0.306
1994	0.4181
1995	-0.4522
1996	0.4019
1997	0.9673
1998	1.433
1999	1.437
2000	1.628
2001	1.261
2002	1.04
2003	1.049
2004	1.092