Year	gross (GPI)
1970	0.854080021381378
1971	0.885890007019043
1972	0.904299974441528
1973	0.930660009384155
1974	0.937539994716644
1975	0.954280018806458
1976	1.00024998188019
1977	1.02917003631592
1978	1.05274999141693
1979	1.06426000595093
1980	1.05432999134064
1981	1.06541001796722
1982	1.0566600561142
1983	1.07194995880127
1984	1.07464003562927
1991	1.08348000049591
1992	1.10827994346619
1993	1.09534001350403
1994	1.07352995872498
1998	1.06174004077911
1999	1.05778002738953
2000	1.03061997890472
2001	1.00864005088806
2002	0.986630022525787
2003	0.987269997596741
2004	0.982400000095367
2005	0.984990000724792
2006	1.00356996059418
2007	1.00881004333496
2008	1.00285995006561
2009	0.999920010566711
2010	1.00610995292664
2011	1.00137996673584
2012	1.02488994598389
2013	1.03752994537354
2014	1.0171400308609
2015	1.00053691864014
2016	1.02679002285004
2017	1.02799999713898
2018	1.02341997623444
2019	1.0338499546051
2020	1.03349995613098