Year	gross (GPI)
1971	1.01955997943878
1972	1.01856005191803
1973	1.01637995243073
1974	1.01085996627808
1975	1.00969004631042
1976	1.00864994525909
1977	1.00700998306274
1978	1.00416994094849
1979	0.998929977416992
1980	1.00002002716064
1981	1.00112998485565
1982	0.999769985675812
1983	1.0014899969101
1984	0.998139977455139
1985	1.01215994358063
1986	0.997430026531219
1987	0.997780025005341
1988	0.998269975185394
1989	0.999639987945557
1990	1.00054001808167
1991	1.0022200345993
1992	1.00314998626709
1993	1.01443994045258
1994	1.01472997665405
1995	1.01447999477386
1996	1.01460003852844
1997	1.01470005512238
1998	1.03453004360199
1999	1.02998995780945
2000	1.02560997009277
2001	1.02548003196716
2002	1.0273300409317
2003	1.02555000782013
2004	0.995260000228882
2005	0.996999979019165
2006	0.997550010681152
2007	0.997219979763031
2008	0.994759976863861
2009	0.995090007781982
2010	0.994759976863861
2011	0.996010005474091
2012	0.998449981212616
2013	1.05919003486633
2014	1.05586004257202
2015	1.0417799949646
2016	1.02603995800018
2017	1.01347994804382
2018	1.01763999462128
2019	1.03957998752594
2020	1.0529899597168