Year	gross (GPI)
1975	0.723879992961884
1976	0.722060024738312
1977	0.741760015487671
1978	0.772889971733093
1979	0.768850028514862
1980	0.754890024662018
1981	0.727739989757538
1982	0.72146999835968
1983	0.735090017318726
1984	0.742060005664825
1985	0.754909992218018
1986	0.753180027008057
1987	0.778039991855621
1988	0.783339977264404
1989	0.794080018997192
1990	0.795319974422455
1991	0.802649974822998
1992	0.820379972457886
1993	0.828649997711182
1994	0.864040017127991
1995	0.880299985408783
1996	0.894339978694916
1997	0.901059985160828
1998	0.918889999389648
1999	0.935850024223328
2000	0.943679988384247
2001	0.948050022125244
2002	0.952390015125275
2003	0.957109987735748
2004	0.970130026340485
2005	0.982469975948334
2006	0.993789970874786
2007	0.999949991703033
2008	1.00628995895386
2009	1.01510000228882
2010	0.997510015964508
2011	1.00137996673584
2012	1.00855994224548
2013	1.00687003135681
2014	1.01454997062683
2015	1.01521003246307
2016	1.01969003677368
2017	1.01996004581451
2018	1.02260994911194
2019	1.02219998836517
2020	1.01946997642517