Year	gross (GPI)
1970	0.636929988861084
1971	0.636990010738373
1972	0.655229985713959
1973	0.65201997756958
1974	0.649800002574921
1975	0.655910015106201
1976	0.661939978599548
1977	0.686029970645905
1978	0.697929978370667
1979	0.703230023384094
1980	0.713649988174438
1981	0.735249996185303
1982	0.755379974842072
1983	0.738640010356903
1984	0.759930014610291
1985	0.754949986934662
1986	0.760519981384277
1987	0.769550025463104
1988	0.783659994602203
1989	0.789759993553162
1990	0.797819972038269
1991	0.8089200258255
1992	0.814769983291626
1993	0.819540023803711
1994	0.824949979782104
1995	0.817929983139038
1996	0.81810998916626
1997	0.824010014533997
1998	0.829219996929169
1999	0.846509993076324
2000	0.854629993438721
2001	0.861689984798431
2002	0.86505001783371
2003	0.874270021915436
2004	0.873709976673126
2005	0.895529985427856
2006	0.908590018749237
2007	0.914849996566772
2008	0.921310007572174
2009	0.929480016231537
2010	0.938180029392242
2011	0.942210018634796
2012	0.945200026035309
2013	0.948170006275177
2014	0.94990998506546
2015	0.95687997341156
2016	0.957799971103668
2017	0.955529987812042
2018	0.953499972820282
2019	0.956679999828339
2020	0.95949000120163