Year	Years
1960	1.895
1961	2.788
1962	2.862
1963	3.292
1964	2.754
1965	3.057
1966	3.586
1967	2.648
1968	2.558
1969	3.218
1970	1.721
1971	1.582
1972	1.886
1973	2.046
1974	2.19
1975	1.406
1976	0.9768
1977	1.208
1978	1.296
1979	0.4762
1980	0.8192
1981	0.9063
1982	0.6122
1983	0.4552
1984	0.4102
1985	0.6506
1986	0.7807
1987	1.194
1988	1.337
1989	1.163
1990	0.98
1991	0.5153
1992	0.4374
1993	0.497
1994	0.4682
1995	0.7877
1996	0.8262
1997	1.014
1998	0.9413
1999	1.507
2000	1.749
2001	2.209
2002	2.645
2003	2.407
2004	2.31