Year	gross (GPI)
1971	0.840059995651245
1972	0.828459978103638
1973	0.823159992694855
1974	0.834879994392395
1975	0.812049984931946
1976	0.802500009536743
1977	0.803979992866516
1978	0.799860000610352
1979	0.810270011425018
1980	0.818650007247925
1981	0.827549993991852
1982	0.821479976177216
1983	0.820519983768463
1984	0.820559978485107
1985	0.801789999008179
1987	0.787150025367737
1988	0.826150000095367
1989	0.834020018577576
1990	0.843150019645691
1991	0.855319976806641
1992	0.871450006961823
1993	0.882130026817322
1994	0.888679981231689
1995	0.89860999584198
1999	0.92315000295639
2000	0.931289970874786
2001	0.941309988498688
2002	0.941500008106232
2003	0.946219980716705
2004	0.940609991550446
2005	0.959569990634918
2006	0.98132997751236
2007	0.982729971408844
2008	0.98360002040863
2009	0.98387998342514
2011	0.990649998188019
2012	0.998080015182495
2013	0.999270021915436
2014	0.999409973621368
2015	0.999639987945557
2016	1.01233994960785
2017	1.01010000705719
2018	1.01215994358063
2019	1.01385998725891
2020	1.01759004592896