Year	gross (GPI)
1970	0.777909994125366
1971	0.777499973773956
1972	0.773239970207214
1973	0.775690019130707
1974	0.780139982700348
1975	0.767830014228821
1976	0.76094001531601
1977	0.756240010261536
1978	0.747399985790253
1979	0.740149974822998
1980	0.741680026054382
1981	0.740989983081818
1982	0.744109988212585
1983	0.749670028686523
1984	0.753809988498688
1985	0.760850012302399
1986	0.770489990711212
1987	0.779399991035461
1988	0.790340006351471
1989	0.8021399974823
1990	0.829320013523102
1991	0.837239980697632
1992	0.848720014095306
1993	0.851050019264221
1994	0.84741997718811
1995	0.872049987316132
1996	0.872780025005341
1997	0.870429992675781
1998	0.866859972476959
1999	0.85809999704361
2000	0.848450005054474
2001	0.839410006999969
2002	0.837670028209686
2003	0.831809997558594
2004	0.818899989128113
2005	0.817049980163574
2006	0.81564998626709
2007	0.807969987392426
2008	0.820330023765564
2009	0.827509999275208
2010	0.838620007038116
2011	0.852720022201538
2012	0.860400021076202
2013	0.877089977264404
2014	0.882290005683899
2015	0.878520011901855
2016	0.889829993247986
2017	0.892059981822968
2018	0.892270028591156
2019	0.888279974460602
2020	0.893459975719452