Year	gross (GPI)
1971	0.568300008773804
1972	0.578840017318726
1973	0.585629999637604
1974	0.589640021324158
1975	0.595619976520538
1976	0.589559972286224
1977	0.577040016651154
1979	0.586889982223511
1980	0.600679993629456
1981	0.589290022850037
1982	0.592469990253448
1983	0.588440001010895
1984	0.588490009307861
1985	0.591040015220642
1986	0.589219987392426
1994	0.638949990272522
1999	0.6841099858284
2000	0.700230002403259
2001	0.712759971618652
2003	0.737219989299774
2004	0.766600012779236
2005	0.782329976558685
2006	0.799489974975586
2007	0.817929983139038
2008	0.839980006217957
2009	0.856069982051849
2010	0.877110004425049
2011	0.89341002702713
2012	0.914619982242584
2013	0.936890006065369
2014	0.948300004005432
2015	0.960349977016449
2016	0.971310019493103
2017	0.982140004634857
2018	0.989130020141602
2019	1.00651001930237
2020	1.0248099565506
2021	1.04399132728577