Year	gross (GPI)
1971	0.885909974575043
1972	0.872590005397797
1974	0.89029997587204
1975	0.87322998046875
1976	0.862649977207184
1977	0.917349994182587
1978	0.918340027332306
1979	0.932190001010895
1980	0.942390024662018
1981	0.951359987258911
1982	0.94922000169754
1983	0.933430016040802
1984	0.93682998418808
1985	0.936179995536804
1986	0.948710024356842
1987	0.952920019626617
1988	0.956149995326996
1989	0.963169991970062
1990	0.962310016155243
1991	0.97122997045517
1992	0.958710014820099
1993	0.962419986724854
1994	0.960650026798248
1995	0.963639974594116
1996	0.96220999956131
1997	0.964709997177124
1998	0.972459971904755
1999	0.981540024280548
2000	0.989459991455078
2001	0.996200025081635
2002	1.00137996673584
2003	1.00969004631042
2004	1.00506997108459
2005	1.00454998016357
2006	1.00862002372742
2007	1.01373994350433
2008	1.01976001262665
2009	1.0246000289917
2010	1.02506005764008
2011	1.02425003051758
2012	1.02397000789642
2013	1.02079999446869
2014	1.02283000946045
2015	1.02982997894287
2016	1.03638005256653
2017	1.0391800403595
2018	1.04627001285553
2019	1.05191004276276
2020	1.05410003662109