Year	gross (GPI)
1970	0.803489983081818
1971	0.80417001247406
1972	0.785309970378876
1973	0.778859972953796
1974	0.766369998455048
1975	0.751699984073639
1976	0.748120009899139
1977	0.742240011692047
1978	0.724430024623871
1979	0.715330004692078
1980	0.714079976081848
1981	0.716530025005341
1982	0.70278000831604
1983	0.703509986400604
1984	0.693769991397858
1985	0.681280016899109
1986	0.679069995880127
1987	0.677789986133575
1988	0.676329970359802
1989	0.677359998226166
1990	0.655910015106201
1991	0.6667600274086
1992	0.682590007781982
1993	0.689310014247894
1994	0.72732001543045
1995	0.728990018367767
1996	0.73650997877121
1997	0.743889987468719
1998	0.760299980640411
1999	0.773689985275269
2000	0.782490015029907
2001	0.783479988574982
2002	0.803390026092529
2003	0.782339990139008
2004	0.784060001373291
2005	0.784680008888245
2006	0.801800012588501
2007	0.799099981784821
2008	0.784770011901855
2009	0.778739988803864
2010	0.76952999830246
2011	0.754109978675842
2012	0.79009997844696
2013	0.802049994468689
2014	0.799239993095398
2015	0.800570011138916
2016	0.812420010566711
2017	0.830320000648499
2018	0.841350018978119
2019	0.846300005912781
2020	0.85878998041153
2021	0.856750011444092