Year	gross (GPI)
1971	0.382820010185242
1972	0.390100002288818
1973	0.414709985256195
1974	0.421420007944107
1975	0.429309993982315
1976	0.448210000991821
1977	0.42059999704361
1978	0.427769988775253
1979	0.451319992542267
1980	0.463699996471405
1981	0.484160006046295
1982	0.49099001288414
1983	0.500869989395142
1984	0.495370000600815
1985	0.529420018196106
1986	0.452039986848831
1987	0.425760000944138
1988	0.519720017910004
1989	0.53930002450943
1990	0.555360019207001
1991	0.610450029373169
2001	0.800119996070862
2002	0.825649976730347
2003	0.876049995422363
2004	0.814930021762848
2005	0.8473299741745
2006	0.883830010890961
2007	0.76706999540329
2008	0.938220024108887
2009	0.905179977416992
2010	0.924929976463318
2011	0.921079993247986
2012	0.910549998283386
2013	0.910929977893829
2014	0.913150012493134
2015	0.981029987335205
2016	1.0390100479126
2017	1.04560995101929
2018	1.05162000656128
2020	0.987240016460419
2022	1.01102995872498