Year	Years
1960	3.638
1961	3.106
1962	2.606
1963	1.542
1964	1.707
1965	1.729
1966	2.567
1967	2.488
1968	1.958
1969	2.364
1970	2.359
1971	3.039
1972	3.187
1973	3.156
1974	3.156
1975	2.598
1976	2.483
1977	2.923
1978	2.834
1979	2.8
1980	2.106
1981	1.47
1982	0.06333
1983	-0.3021
1984	-0.1766
1985	-0.3664
1986	-0.4254
1987	-1.006
1988	-1.211
1989	-1.158
1990	-0.9307
1991	-0.536
1992	0.9025
1993	1.459
1994	1.366
1995	1.716
1996	1.657
1997	1.833
1998	2.174
1999	2.775
2000	2.763
2001	2.571
2002	2.143
2003	2.206
2004	2.094