Year	gross (GPI)
1970	0.676590025424957
1971	0.676540017127991
1972	0.656610012054443
1973	0.643199980258942
1974	0.62897002696991
1975	0.618849992752075
1976	0.609380006790161
1977	0.596090018749237
1978	0.577049970626831
1979	0.557200014591217
1980	0.548829972743988
1981	0.538150012493134
1982	0.531949996948242
1983	0.529659986495972
1984	0.528259992599487
1985	0.521619975566864
1986	0.52318000793457
1987	0.538839995861053
1988	0.52156001329422
1989	0.51867002248764
1990	0.517000019550323
1991	0.53591001033783
1992	0.555469989776611
1993	0.570259988307953
1994	0.605130016803741
1995	0.615920007228851
1996	0.630509972572327
1997	0.644349992275238
1998	0.665859997272491
1999	0.689490020275116
2000	0.693750023841858
2001	0.690190017223358
2002	0.697109997272491
2003	0.683539986610413
2004	0.694140017032623
2005	0.696799993515015
2006	0.708259999752045
2007	0.708689987659454
2008	0.702019989490509
2009	0.709290027618408
2010	0.705709993839264
2011	0.690590023994446
2012	0.712329983711243
2013	0.721520006656647
2014	0.72026002407074
2015	0.729870021343231
2016	0.741129994392395
2017	0.749779999256134
2018	0.762510001659393
2019	0.773930013179779
2020	0.787450015544891
2021	0.789200007915497