Year	Years
1960	0.08436
1961	1.928
1962	2.831
1963	3.772
1964	4.376
1965	4.48
1966	4.306
1967	5.225
1968	5.86
1969	5.794
1970	5.7
1971	4.426
1972	3.494
1973	2.52
1974	1.964
1975	2.513
1976	3.509
1977	3.094
1978	2.841
1979	2.866
1980	3.064
1981	2.592
1982	2.984
1983	2.584
1984	2.597
1985	2.487
1986	2.495
1987	1.826
1988	1.958
1989	1.608
1990	1.635
1991	2.306
1992	0.9998
1993	0.9883
1994	1.741
1995	0.611
1996	0.8205
1997	0.8059
1998	0.5868
1999	0.3898
2000	0.2289
2001	0.1736
2002	0.9752
2003	1.485