Year	gross (GPI)
1971	0.633239984512329
1972	0.701900005340576
1974	0.693989992141724
1975	0.686649978160858
1976	0.657149970531464
1977	0.790910005569458
1978	0.834020018577576
1979	0.811980009078979
1980	0.819360017776489
1981	0.886560022830963
1982	0.896740019321442
1983	0.893499970436096
1984	0.908569991588593
1985	0.885559976100922
1986	0.922280013561249
1987	0.931980013847351
1988	0.941479980945587
1989	0.959670007228851
1990	0.971560001373291
1991	0.986299991607666
1992	0.953410029411316
1993	0.968810021877289
1994	0.974330008029938
1995	0.974910020828247
1996	0.968420028686523
1997	0.972220003604889
1998	0.987389981746674
1999	1.00492000579834
2000	1.01759004592896
2001	1.02854001522064
2002	1.03848004341125
2003	1.05648994445801
2004	1.04212999343872
2005	1.04304003715515
2006	1.05280005931854
2007	1.06327998638153
2008	1.07455003261566
2009	1.08292996883392
2010	1.07822000980377
2011	1.07229995727539
2012	1.06710004806519
2013	1.05704998970032
2014	1.05657994747162
2015	1.06598997116089
2016	1.07486999034882
2017	1.07510995864868
2018	1.08762001991272
2019	1.09623003005981
2020	1.1015499830246