Year	gross (GPI)
1970	0.754400014877319
1971	0.827920019626617
1972	0.865869998931885
1973	0.847370028495789
1974	0.837999999523163
1975	0.921909987926483
1976	0.929790019989014
1977	0.928080022335052
1978	1.01944994926453
1979	1.00404000282288
1980	1.03500998020172
1981	1.14066004753113
1982	1.1363799571991
1983	1.15683996677399
1984	1.14219999313354
1985	1.11730003356934
1986	1.13516998291016
1987	1.14682996273041
1999	1.40173995494843
2000	1.36731004714966
2001	1.33592998981476
2002	1.33747005462646
2003	1.34669005870819
2004	1.30524003505707
2005	1.32123994827271
2006	1.35178005695343
2007	1.35222005844116
2008	1.35339999198914
2009	1.34807002544403
2010	1.34685003757477
2011	1.36926996707916
2012	1.37328004837036
2013	1.38708996772766
2014	1.3909900188446
2015	1.39732003211975
2016	1.40629005432129
2017	1.40893995761871
2018	1.40596997737885
2019	1.41640996932983
2020	1.42865002155304
2021	1.46200001239777