Year	gross (GPI)
1970	0.913299977779388
1971	0.905290007591248
1972	0.930710017681122
1973	0.927869975566864
1974	0.952030003070831
1975	0.962069988250732
1976	0.957430005073547
1977	0.962849974632263
1978	0.96341997385025
1979	0.967599987983704
1980	0.966560006141663
1981	0.967230021953583
1982	0.97172999382019
1983	0.974849998950958
1984	0.974919974803925
1985	0.979139983654022
1986	0.981010019779205
1987	0.981459975242615
1988	0.979839980602264
1989	0.978479981422424
1990	0.978990018367767
1991	0.975510001182556
1992	0.980040013790131
1993	0.980840027332306
1994	0.985419988632202
1995	0.989000022411346
1996	0.989390015602112
1997	0.989790022373199
1998	0.99838000535965
1999	1.00577998161316
2000	1.00881004333496
2001	1.0042599439621
2002	1.00603997707367
2003	1.00220000743866
2004	0.999000012874603
2005	1.0053299665451
2006	1.00427997112274
2007	0.996730029582977
2008	1.00230002403259
2009	1.01026999950409
2010	1.00855004787445
2011	1.00913000106812
2012	1.016970038414
2013	1.01777005195618
2014	1.01328003406525
2015	1.01247000694275
2016	1.01346004009247
2017	1.01481997966766
2018	1.01511001586914
2019	1.01504004001617
2020	1.01818001270294