Year	gross (GPI)
1971	1.01215004920959
1972	1.01253998279572
1973	1.00104999542236
1974	0.998950004577637
1975	1.01489996910095
1976	1.01819002628326
1977	1.01861000061035
1978	1.0222100019455
1979	1.02254998683929
1980	1.03249001502991
1981	1.01900005340576
1983	1.02161002159119
1984	1.02319002151489
1985	1.01839005947113
1986	1.01778995990753
1987	0.988189995288849
1988	1.00274002552032
1989	1.0076299905777
1990	0.999960005283356
1991	1.00690996646881
1993	0.975130021572113
1999	1.00265002250671
2000	0.997560024261475
2001	0.992129981517792
2002	0.998099982738495
2003	1.00151002407074
2004	1.00326001644135
2005	0.995180010795593
2007	1.00449001789093