Year	gross (GPI)
1970	0.678669989109039
1971	0.679989993572235
1972	0.684689998626709
1973	0.68860000371933
1974	0.690199971199036
1975	0.700709998607636
1976	0.708530008792877
1977	0.712149977684021
1978	0.71603000164032
1979	0.723640024662018
1980	0.727609992027283
1981	0.735769987106323
1982	0.73869001865387
1983	0.749650001525879
1984	0.749989986419678
1985	0.758379995822906
1986	0.767809987068176
1987	0.774290025234222
1988	0.783510029315948
1989	0.78600001335144
1990	0.792639970779419
1991	0.804520010948181
1992	0.812529981136322
1993	0.823109984397888
1994	0.831700026988983
1995	0.835430026054382
1996	0.839569985866547
1997	0.851930022239685
1998	0.861259996891022
1999	0.873250007629395
2000	0.878759980201721
2001	0.886280000209808
2002	0.896480023860931
2003	0.932969987392426
2004	0.934909999370575
2005	0.941799998283386
2006	0.94827002286911
2007	0.956110000610352
2008	0.968879997730255
2009	0.980130016803741
2010	0.984899997711182
2011	0.989929974079132
2012	0.991890013217926
2013	1.01769995689392
2014	1.018669962883
2015	1.01923000812531
2016	1.03110003471375
2017	1.02734005451202
2018	1.00275003910065
2019	1.00501000881195
2020	1.00110995769501