Year	gross (GPI)
1971	0.935570001602173
1972	0.969290018081665
1973	0.929650008678436
1977	0.93818998336792
1978	0.949559986591339
1979	0.969120025634766
1980	0.94871997833252
1981	0.979910016059875
1982	0.988510012626648
1983	0.990019977092743
1984	0.98513001203537
1985	0.998610019683838
1986	1.0056300163269
1987	0.996919989585876
1988	1.00703001022339
1989	1.01205003261566
1990	1.01706004142761
1991	1.02236998081207
1992	1.02298998832703
1995	1.0565299987793
1996	1.05814003944397
1998	1.02866995334625
1999	1.07220995426178
2000	1.06449997425079
2001	1.09011995792389
2002	1.07585000991821
2003	1.07272005081177
2004	1.09883999824524
2005	1.06909000873566
2006	1.07026994228363
2007	1.08939003944397
2008	1.07184994220734