Year	gross (GPI)
1970	0.0540100000798702
1971	0.243699997663498
1972	0.219819992780685
1974	0.315429985523224
1976	0.374099999666214
1977	0.389919996261597
1978	0.391279995441437
1979	0.419019997119904
1982	0.470620006322861
1983	0.488389998674393
1984	0.504270017147064
1985	0.532260000705719
1986	0.548189997673035
1988	0.604470014572144
1991	0.598469972610474
1992	0.747089982032776
1993	0.759239971637726
1994	0.775089979171753
1995	0.783949971199036
1996	0.800329983234406
1997	0.820179998874664
1998	0.836989998817444
1999	0.855949997901917
2000	0.876980006694794
2001	0.897700011730194
2002	0.915409982204437
2003	0.944909989833832
2004	0.972169995307922
2005	0.974820017814636
2006	0.988479971885681
2007	0.9932000041008
2008	1.01128995418549
2009	1.01814997196198
2010	1.02275002002716
2011	1.01408004760742
2012	1.01487994194031
2013	1.00978004932404
2014	1.01405000686646
2015	1.0107319355011
2016	1.00471997261047
2017	0.998650312423706
2018	1.00030362606049
2019	1.00695478916168
2020	1.01517379283905
2021	1.03652012348175