Year	gross (GPI)
1980	1.01684999465942
1981	1.01999998092651
1982	1.01016998291016
1983	0.9932000041008
1984	1.00539004802704
1985	1.01199996471405
1986	1.00943005084991
1987	0.994109988212585
1988	0.993690013885498
1989	0.991850018501282
1990	0.99413001537323
1991	0.982330024242401
1992	0.98158997297287
1993	0.981010019779205
1994	0.989849984645844
1995	0.989350020885468
1996	0.987489998340607
1997	1.005499958992
1998	1.02320003509521
1999	1.02521002292633
2000	0.9860600233078
2001	0.997080028057098
2002	1.00811994075775
2003	1.00141000747681
2004	0.994690001010895
2005	0.989449977874756
2006	1.00627994537354
2007	1.00423002243042
2008	1.00141000747681
2009	1.00356996059418
2010	1.00129997730255
2011	0.998459994792938
2012	0.995850026607513
2013	0.99330997467041
2014	0.997900009155273
2015	1.00044000148773
2016	0.998539984226227
2017	0.992799997329712
2018	0.998549997806549
2019	1.00591003894806
2020	0.994949996471405