Year	gross (GPI)
1970	0.94174998998642
1971	0.96399998664856
1972	0.977479994297028
1973	0.979449987411499
1974	0.994769990444183
1975	1.04059994220734
1976	1.04168999195099
1977	1.01418995857239
1978	1.02059996128082
1979	1.04040002822876
1980	1.03863000869751
1981	1.04888999462128
1982	1.04576003551483
1983	1.04848003387451
1984	1.04544997215271
1985	1.02470004558563
1986	1.04695999622345
1987	1.04692995548248
1988	1.04921996593475
1989	1.05288004875183
1990	1.06106996536255
1991	1.06826996803284
1992	1.06465005874634
1993	1.0672299861908
1994	1.06792998313904
1995	1.06866002082825
1996	1.06137001514435
1997	1.06344997882843
1998	1.06517994403839
1999	1.06036996841431
2000	1.06597995758057
2001	1.06105005741119
2002	1.06107997894287
2003	1.07780003547668
2004	1.07305002212524
2005	1.07474005222321
2006	1.07607996463776
2007	1.09114003181458
2008	1.09564995765686
2009	1.09219002723694
2010	1.0830899477005
2011	1.07993996143341
2012	1.06853997707367
2013	1.05967998504639
2014	1.05894994735718
2015	1.05524003505707
2016	1.04870998859406
2017	1.04282999038696
2018	1.04487001895905
2019	1.04920995235443
2020	1.05212998390198