Year	gross (GPI)
1971	0.315349996089935
1973	0.320630013942719
1974	0.329259991645813
1975	0.358040004968643
1976	0.366120010614395
1977	0.413080006837845
1978	0.473489999771118
1979	0.417499989271164
1980	0.409280002117157
1981	0.416500002145767
1983	0.437189996242523
1984	0.438659995794296
1985	0.431859999895096
1986	0.423970013856888
1987	0.431059986352921
1988	0.41185998916626
1989	0.402029991149902
1990	0.462179988622665
1991	0.489170014858246
1992	0.525359988212585
1993	0.532959997653961
1994	0.550140023231506
1995	0.555159986019135
1996	0.630519986152649
2008	0.941820025444031
2009	0.967249989509583
2010	0.958620011806488
2021	1.17850005626678