Year	Years
1980	2.777
1981	3.138
1982	3.613
1983	3.33
1984	3.539
1985	3.488
1986	4.029
1987	3.601
1988	3.376
1989	3.231
1990	2.342
1991	0.5886
1992	-1.128
1993	-1.862
1994	-2.081
1995	-1.837
1996	-2.441
1997	-2.266
1998	-2.286
1999	-2.103
2000	-1.627
2001	-0.4731
2002	0.9794
2003	1.851