Year	gross (GPI)
1971	0.59154999256134
1972	0.607909977436066
1973	0.661409974098206
1974	0.692470014095306
1975	0.721040010452271
1978	0.75994998216629
1979	0.747529983520508
1980	0.776849985122681
1981	0.828970015048981
1982	0.830449998378754
1983	0.861859977245331
1984	0.880909979343414
1985	0.863839983940125
1986	0.878000020980835
1987	0.923900008201599
1988	0.936940014362335
1989	0.907119989395142
1990	0.961059987545013
1991	0.968729972839355
1993	0.993860006332397
1994	1.01050996780396
1995	1.0124499797821
1996	1.02970004081726
1999	1.12663996219635
2000	1.11033999919891
2001	1.13141000270844
2002	1.14286994934082
2003	1.14858996868134
2004	1.16425001621246
2005	1.18326997756958
2006	1.19087994098663
2007	1.19723999500275
2008	1.20142996311188
2009	1.19456005096436
2010	1.20782995223999
2011	1.21293997764587
2012	1.22122001647949
2013	1.23296999931335
2014	1.23636996746063
2015	1.23844003677368
2016	1.24030005931854
2017	1.240110039711
2018	1.2364000082016
2019	1.25319004058838
2020	1.25312995910645
2021	1.26310002803802