Year	gross (GPI)
1976	0.820949971675873
1977	0.826040029525757
1978	0.830439984798431
1979	0.818159997463226
1980	0.811959981918335
1981	0.794979989528656
1982	0.781080007553101
1983	0.777639985084534
1984	0.781639993190765
1985	0.787370026111603
1986	0.808640003204346
1987	0.826499998569489
1988	0.833199977874756
1989	0.842719972133636
1990	0.848609983921051
1991	0.860360026359558
1992	0.874170005321503
1993	0.881250023841858
1994	0.901910006999969
1995	0.915570020675659
1996	0.928520023822784
1997	0.935779988765717
2001	0.964619994163513
2006	0.988039970397949
2007	0.991550028324127
2008	0.996969997882843
2009	1.00335001945496
2010	0.98895001411438
2011	0.992420017719269
2012	0.997179985046387
2013	1.00609004497528
2014	1.00947999954224
2015	1.01157999038696
2016	1.01013994216919
2017	1.01321995258331
2018	1.01431000232697
2019	1.01529002189636
2020	1.01286995410919
2021	1.01161003112793