Year	Years
1960	3.338
1961	3.251
1962	3.794
1963	3.851
1964	3.721
1965	3.231
1966	2.768
1967	2.77
1968	3.599
1969	3.318
1970	3.288
1971	3.028
1972	3.023
1973	3.023
1974	2.68
1975	1.649
1976	1.494
1977	1.588
1978	1.553
1979	1.478
1980	1.323
1981	1.041
1982	0.5596
1983	0.3214
1984	0.4893
1985	1.669
1986	1.838
1987	1.591
1988	1.59
1989	1.558
1990	1.333
1991	1.081
1992	1.187
1993	1.097
1994	0.9545
1995	0.735
1996	0.5956
1997	0.6595
1998	0.7278
1999	0.4608
2000	0.4931
2001	0.7327
2002	0.8065
2003	0.8068
2004	0.8801