Year	gross (GPI)
1970	0.5244500041008
1971	0.523000001907349
1972	0.490979999303818
1973	0.486600011587143
1974	0.489100009202957
1975	0.47257000207901
1976	0.439830005168915
1980	0.538550019264221
2001	0.970459997653961
2002	1.05634999275208
2003	1.05638003349304
2004	1.01024997234344
2005	1.00924003124237
2006	1.04243004322052
2016	1.03468000888824
2017	1.07132995128632