Year	gross (GPI)
1970	0.534049987792969
1971	0.541000008583069
1972	0.549530029296875
1973	0.558640003204346
1974	0.569490015506744
1975	0.591260015964508
1976	0.600570023059845
1977	0.599049985408783
1978	0.607529997825623
1979	0.61422997713089
1980	0.619480013847351
1981	0.629890024662018
1982	0.63043999671936
1983	0.66237998008728
1984	0.648069977760315
1985	0.65583997964859
1986	0.668839991092682
1987	0.676999986171722
1988	0.687449991703033
1989	0.699400007724762
1990	0.709609985351563
1991	0.718970000743866
1992	0.727989971637726
1993	0.738059997558594
1994	0.755739986896515
1995	0.765919983386993
1996	0.77727997303009
1997	0.797559976577759
1998	0.819490015506744
1999	0.839999973773956
2000	0.849470019340515
2001	0.857249975204468
2002	0.870930016040802
2003	0.8992999792099
2004	0.900110006332397
2005	0.911930024623871
2006	0.920520007610321
2007	0.933179974555969
2008	0.944920003414154
2009	0.963859975337982
2010	0.969120025634766
2011	0.976300001144409
2012	0.980629980564117
2013	1.00085997581482
2014	1.00932002067566
2015	1.009889960289
2016	1.01549005508423
2017	1.01396000385284
2018	1.01769995689392
2019	1.01930999755859
2020	1.01084005832672