Year	gross (GPI)
1971	0.175459995865822
1972	0.160199999809265
1973	0.214959993958473
1976	0.252330005168915
1977	0.216000005602837
1978	0.230039998888969
1979	0.289739996194839
1980	0.283520013093948
1983	0.340479999780655
1984	0.366970002651215
1987	0.396239995956421
1988	0.418350011110306
1989	0.437649995088577
1990	0.425850003957748
1999	0.556410014629364
2001	0.672999978065491
2003	0.577289998531342
2019	1.20079696178436