Year	Years
1960	5.266
1961	4.85
1962	5.365
1963	6.744
1964	5.923
1965	5.988
1966	5.964
1967	5.919
1968	6.1
1969	7.283
1970	6.508
1971	5.695
1972	5.529
1973	5.358
1974	5.414
1975	4.772
1976	4.365
1977	4.15
1978	3.627
1979	2.764
1980	2.606
1981	2.19
1982	1.515
1983	0.9527
1984	0.6082
1985	0.8575
1986	0.898
1987	1.305
1988	1.771
1989	2.269
1990	2.47
1991	2.786
1992	2.777
1993	2.497
1994	2.573
1995	2.629
1996	2.555
1997	2.402
1998	2.352
1999	2.328
2000	2.41
2001	2.444
2002	2.531
2003	2.844
2004	2.797