Year	gross (GPI)
1970	0.92892998456955
1971	0.931029975414276
1972	0.927690029144287
1973	0.935859978199005
1974	0.949710011482239
1975	0.958419978618622
1976	0.964460015296936
1977	0.97351998090744
1978	0.985530018806458
1979	0.992749989032745
1980	0.995459973812103
1981	0.98853999376297
1982	0.989220023155212
1983	0.982940018177032
1984	0.987890005111694
1985	0.987219989299774
1986	0.993120014667511
1987	0.993920028209686
1988	0.99456000328064
1989	1.00207996368408
1990	0.995360016822815
1991	0.987600028514862
1992	0.983299970626831
1993	0.97623997926712
1994	0.980289995670319
1995	0.977779984474182
1996	0.969980001449585
1997	0.970030009746552
1998	0.958880007266998
1999	0.958230018615723
2000	0.94498997926712
2001	0.952430009841919
2002	0.929489970207214
2003	0.944530010223389
2004	0.930850028991699
2005	0.927119970321655
2006	0.916710019111633
2007	0.912479996681213
2009	0.904999971389771
2010	0.90745997428894
2011	0.885330021381378
2012	0.903370022773743
2013	0.902899980545044
2014	0.907159984111786
2015	0.909070014953613
2016	0.918160021305084
2017	0.920210003852844
2018	0.922640025615692
2019	0.922559976577759