Year	Years
1980	1.615
1981	0.872
1982	1.417
1983	1.733
1984	2.447
1985	3.022
1986	3.141
1987	0.8986
1988	0.6943
1989	1.57
1990	1.732
1991	2.645
1992	2.472
1993	1.859
1994	1.016
1995	0.7365
1996	0.7155
1997	3.191
1998	3.534
1999	3.42
2000	3.444
2001	3.277
2002	3.023
2003	3.258