Year	gross (GPI)
1973	1.05692005157471
1974	1.08522999286652
1975	1.09739995002747
1976	1.10180997848511
1977	1.09064996242523
1978	1.07744002342224
1979	1.08697998523712
1980	1.10092997550964
1983	1.07894003391266
1984	1.08149003982544
1985	1.0728600025177
1986	1.074010014534
1987	1.07118999958038
1988	1.06837999820709
1989	1.07168996334076
1990	1.06236004829407
1991	1.05109000205994
1992	1.04346001148224
1993	1.0514600276947
1994	1.04053997993469
1999	0.992820024490356
2000	1.00090003013611
2001	0.994279980659485
2002	0.986240029335022
2003	0.977720022201538
2004	0.996270000934601
2005	0.994099974632263
2006	0.995959997177124
2007	1.00339996814728
2008	1.01671004295349
2009	1.02151000499725
2010	1.024129986763
2011	1.02030003070831
2012	1.02040994167328
2013	1.01978003978729
2014	1.0153900384903
2015	1.01003003120422
2016	1.01718997955322
2017	1.01699995994568
2018	1.01742994785309
2019	1.01716005802155
2020	1.01514995098114