Year	gross (GPI)
1970	0.490610003471375
1971	0.489499986171722
1972	0.490209996700287
1973	0.487740010023117
1974	0.476960003376007
1975	0.489270001649857
1976	0.496410012245178
1977	0.502860009670258
1978	0.512889981269836
1979	0.491039991378784
1980	0.498600006103516
1981	0.500989973545074
1982	0.51842999458313
1983	0.494549989700317
1984	0.487580001354218
1985	0.48938000202179
1986	0.485449999570847
1987	0.506240010261536
1988	0.490850001573563
1989	0.486930012702942
1990	0.494230002164841
1991	0.492489993572235
1992	0.497310012578964
1993	0.52030998468399
1994	0.534389972686768
1995	0.554300010204315
1996	0.577319979667664
1997	0.602680027484894
1998	0.626670002937317
1999	0.655089974403381
2000	0.672150015830994
2001	0.679679989814758
2002	0.680410027503967
2003	0.676980018615723
2004	0.684310019016266
2005	0.701730012893677
2006	0.707350015640259
2007	0.704389989376068
2008	0.705460011959076
2009	0.715990006923676
2010	0.724870026111603
2011	0.732729971408844
2012	0.749480009078979
2013	0.758989989757538
2014	0.76911997795105
2015	0.758889973163605
2016	0.759609997272491
2017	0.763800024986267
2018	0.773630023002625
2019	0.798810005187988
2020	0.816309988498688
2021	0.825879991054535
2022	0.834429979324341