Year	Years
1960	-4.559
1961	-2.828
1962	-2.111
1963	-0.8345
1964	-0.1594
1965	-0.8066
1966	-0.8607
1967	-0.7602
1968	-1.059
1969	-1.068
1970	1.794
1971	0.3404
1972	0.2996
1973	0.4264
1974	0.752
1975	2.453
1976	3.306
1977	3.801
1978	5.003
1979	5.045
1980	4.044
1981	3.585
1982	4.156
1983	3.06
1984	2.939
1985	2.403
1986	2.371
1987	2.807
1988	3.076
1989	3.553
1990	4.633
1991	4.997
1992	4.772
1993	5.194
1994	5.222
1995	5.342
1996	5.023
1997	4.261
1998	4.389
1999	3.985
2000	4.357
2001	4.636
2002	3.963
2003	3.877
2004	3.884