Year	Years
1980	3.319
1981	2.537
1982	2.63
1983	2.593
1984	2.502
1985	2.099
1986	1.731
1987	2.035
1988	1.96
1989	1.22
1990	0.5389
1991	0.8751
1992	0.3369
1993	0.5419
1994	0.6725
1995	0.5657
1996	0.5799
1997	0.3889
1998	0.398
1999	1.109
2000	0.7376
2001	0.7711
2002	1.19
2003	1.447