Year	gross (GPI)
1970	0.917900025844574
1971	0.917879998683929
1972	0.917309999465942
1973	0.931659996509552
1974	0.939639985561371
1975	0.955290019512177
1976	0.970889985561371
1977	0.983139991760254
1978	0.998820006847382
1979	1.00146996974945
1980	1.00706005096436
1981	1.01324999332428
1982	1.00978994369507
1983	1.00913000106812
1984	1.00927996635437
1985	1.00928997993469
1986	1.01127994060516
1987	1.00975000858307
1988	1.00679004192352
1989	1.00493001937866
1990	1.00457000732422
1991	1.00574994087219
1992	1.00585997104645
1993	1.00381004810333
1994	1.0013200044632
1995	1.00453996658325
1996	1.00297999382019
1997	1.00821995735168
1998	1.01385998725891
1999	1.01382994651794
2000	1.00385999679565
2001	1.00424003601074
2002	1.00335001945496
2003	1.00428998470306
2004	1.00349998474121
2005	0.999729990959167
2006	0.999949991703033
2007	0.999450027942657
2008	0.998189985752106
2009	0.999629974365234
2010	0.997879981994629
2011	0.9965900182724
2012	0.995599985122681
2013	0.998399972915649
2014	1.00063002109528
2015	1.00040996074677
2016	0.997619986534119
2017	0.995689988136292
2018	0.996959984302521
2019	0.997630000114441
2020	0.996469974517822