Year	Years
1970	1.781
1971	1.657
1972	0.9098
1973	2.375
1974	2.469
1975	0.9365
1976	1.962
1977	2.134
1978	5.08
1979	3.341
1980	5.613
1981	5.353
1982	5.143
1983	3.22
1984	2.433
1985	4.241
1986	4.551
1987	3.441
1988	1.165
1989	2.702
1990	0.6967
1991	0.3302
1992	0.194
1993	1.2
1994	2.044
1995	2.158
1996	1.947
1997	2.539
1998	3.141
1999	3.331
2000	3.36
2001	3.92
2002	3.792
2003	3.964