Year	gross (GPI)
1970	0.596859991550446
1971	0.634850025177002
1972	0.653980016708374
1973	0.679080009460449
1976	0.686070024967194
1977	0.758249998092651
1978	0.783569991588593
1979	0.778050005435944
1980	0.789979994297028
1981	0.797169983386993
1982	0.78847998380661
1983	0.776289999485016
1984	0.778659999370575
1985	0.810869991779327
1986	0.820089995861053
1987	0.82344001531601
1988	0.760299980640411
1989	0.844990015029907
1990	0.78600001335144
1991	0.806140005588531
1992	0.816770017147064
1993	0.804090023040771
1994	0.81521999835968
1995	0.831070005893707
1996	0.85632997751236
1999	0.806930005550385
2000	0.810350000858307
2001	0.826590001583099
2002	0.825600028038025
2003	0.831870019435883
2004	0.837800025939941
2005	0.843209981918335
2006	0.859790027141571
2007	0.882279992103577
2008	0.888109982013702
2009	0.89630001783371
2010	0.908500015735626
2011	0.932770013809204
2012	0.974160015583038
2013	0.974839985370636
2014	0.98539000749588
2015	0.937149107456207
2016	0.942709982395172
2017	0.943077504634857
2018	0.977930009365082
2019	1.00997877120972