Year	Years
1960	2.765
1961	2.825
1962	3.763
1963	3.398
1964	3.552
1965	3.256
1966	3.95
1967	4.02
1968	2.494
1969	2.496
1970	3.032
1971	4.713
1972	4.237
1973	4.05
1974	3.933
1975	3.181
1976	2.537
1977	3.707
1978	5.026
1979	5.359
1980	5.251
1981	4.1
1982	4.125
1983	3.04
1984	2.577
1985	2.959
1986	3.407
1987	3.162
1988	2.535
1989	2.048
1990	1.593
1991	1.168
1992	0.6382
1993	0.9784
1994	0.97
1995	0.6585
1996	0.5957
1997	0.2851
1998	0.9107
1999	1.309
2000	1.727
2001	2.035
2002	2.147
2003	2.498
2004	2.798