Year	gross (GPI)
1970	0.7776899933815
1971	0.776359975337982
1972	0.774609982967377
1973	0.773360013961792
1974	0.774129986763
1975	0.805079996585846
1976	0.81988000869751
1977	0.821879982948303
1978	0.82234001159668
1979	0.826250016689301
1980	0.824129998683929
1981	0.819530010223389
1982	0.81496000289917
1983	0.821590006351471
1984	0.820309996604919
1985	0.821139991283417
1986	0.838199973106384
1987	0.847249984741211
1988	0.85291999578476
1989	0.856260001659393
1990	0.862739980220795
1991	0.871150016784668
1992	0.878589987754822
1993	0.885150015354156
1994	0.89478999376297
1995	0.900479972362518
1996	0.904749989509583
1997	0.912670016288757
1998	0.920780003070831
1999	0.92833000421524
2000	0.93121999502182
2001	0.93503999710083
2002	0.940339982509613
2003	0.963750004768372
2004	0.967660009860992
2005	0.970040023326874
2006	0.974009990692139
2007	0.978929996490479
2008	0.987240016460419
2009	0.996259987354279
2010	0.992839992046356
2011	0.994849979877472
2012	0.997630000114441
2013	1.02050995826721
2014	1.02258002758026
2015	1.02165997028351
2016	1.03178000450134
2017	1.02743995189667
2018	1.00800001621246
2019	1.00849997997284
2020	1.00408005714417