Year	gross (GPI)
1970	0.969860017299652
1971	0.96985000371933
1972	0.977100014686584
1973	0.980329990386963
1974	0.984089970588684
1975	0.986819982528687
1976	0.987139999866486
1977	0.984560012817383
1978	0.985210001468658
1979	0.986500024795532
1980	0.990930020809174
1981	0.988179981708527
1982	0.984070003032684
1983	0.984420001506805
1984	0.982779979705811
1985	0.987789988517761
1986	0.985520005226135
1987	0.985499978065491
1988	0.987500011920929
1989	0.989979982376099
1990	0.9896399974823
1991	0.985840022563934
1992	0.987079977989197
1993	0.983829975128174
1994	0.983020007610321
1995	0.978929996490479
1996	0.980849981307983
1997	0.978359997272491
1998	0.975160002708435
1999	0.974089980125427
2000	0.97393000125885
2001	0.973640024662018
2002	0.974179983139038
2003	0.975669980049133
2004	0.973590016365051
2005	0.976310014724731
2006	0.982580006122589
2007	0.985170006752014
2008	0.99058997631073
2009	0.991089999675751
2010	0.992259979248047
2011	0.990920007228851
2012	1.0008100271225
2013	1.0030699968338
2014	1.00397002696991
2015	1.00562000274658
2016	1.00355994701385
2017	1.0076299905777
2018	1.00849997997284
2019	1.00981998443604
2020	1.01010000705719