Year	gross (GPI)
1970	0.829270005226135
1971	0.829999983310699
1972	0.765550017356873
1973	0.721180021762848
1974	0.707570016384125
1975	0.827660024166107
1976	0.790669977664948
1977	0.802980005741119
1978	0.791930019855499
1980	0.810379981994629
1981	0.757839977741241
1983	0.666819989681244
1991	0.81207001209259
1999	0.87703001499176
2000	1.14130997657776
2001	0.9130499958992
2002	0.944329977035522
2003	0.839869976043701
2004	0.864139974117279
2010	0.997889995574951
2015	1.02690994739532
2020	1.14437997341156