Year	gross (GPI)
1970	0.939599990844727
1971	0.934480011463165
1972	0.933510005474091
1973	0.93818998336792
1974	0.947000026702881
1975	0.943430006504059
1976	0.943390011787415
1977	0.957050025463104
1978	0.973749995231628
1979	0.986720025539398
1980	0.994499981403351
1981	1.00551998615265
1982	1.01584005355835
1983	1.03591001033783
1984	1.0456600189209
1985	1.0464700460434
1986	1.05475997924805
1987	1.05322003364563
1988	1.05147004127502
1989	1.05009996891022
1990	1.04830002784729
1991	1.03892004489899
1992	1.04725003242493
1993	1.05280005931854
1994	1.06043994426727
1995	1.08111000061035
1996	1.08555996417999
1997	1.09607994556427
1998	1.11530995368958
1999	1.12188005447388
2000	1.13065004348755
2001	1.14172995090485
2002	1.16143000125885
2003	1.15851998329163
2004	1.17200005054474
2005	1.17623996734619
2006	1.17804002761841
2007	1.17891001701355
2008	1.18368005752563
2009	1.18308997154236
2010	1.17780995368958
2011	1.1733900308609
2012	1.1565500497818
2013	1.1467399597168
2014	1.13513994216919
2015	1.13075995445251
2016	1.12784004211426
2017	1.12795996665955
2018	1.13112998008728
2019	1.13986003398895
2020	1.14682996273041
2021	1.15803003311157
2022	1.15857994556427