Year	gross (GPI)
1971	1.04531002044678
1972	1.04611003398895
1973	1.04685997962952
1974	1.04745995998383
1975	1.04707002639771
1976	1.04655003547668
1977	1.04588997364044
1978	1.04618000984192
1979	1.04785001277924
1980	1.05069005489349
1982	1.06985998153687
1983	1.07071995735168
1984	1.0681300163269
1985	1.06514000892639
1986	1.06268000602722
1987	1.18163001537323
1988	1.18043005466461
1989	0.94717001914978
1990	0.915650010108948
1991	0.971149981021881
1992	1.04304003715515
1993	1.06833004951477
1994	1.01288998126984
1995	1.03132998943329
1996	1.0353000164032
1997	1.03545999526978
1998	1.05016005039215
1999	1.04525005817413
2000	1.02119994163513
2001	1.03424000740051
2002	1.03104996681213
2003	1.02906000614166
2004	1.01613998413086
2005	1.01847994327545
2006	1.01713001728058
2007	1.01436996459961
2008	1.01339995861053
2009	1.01242995262146
2010	1.00594997406006
2011	1.00206995010376
2012	1.00197005271912
2013	1.00707995891571
2014	1.00463998317719
2015	1.00950002670288
2016	1.00845003128052
2017	1.00715005397797
2018	1.00420999526978
2019	1.00978004932404
2020	1.00972998142242