Year	gross (GPI)
1971	0.432370007038116
1972	0.477479994297028
1973	0.497880011796951
1974	0.546259999275208
1975	0.588509976863861
1976	0.555440008640289
1982	0.726949989795685
1983	0.735400021076202
1984	0.74329000711441
1985	0.734549999237061
1986	0.715219974517822
1987	0.712249994277954
1988	0.721560001373291
1989	0.732779979705811
1990	0.735310018062592
1991	0.721859991550446
1992	0.73062002658844
1993	0.782890021800995
1994	0.77674001455307
1995	0.778949975967407
1996	0.753530025482178
1997	0.749610006809235
1998	0.756680011749268
1999	0.717999994754791
2000	0.740209996700287
2001	0.753099977970123
2002	0.767390012741089
2004	0.788489997386932
2005	0.817239999771118
2006	0.818819999694824
2007	0.888899981975555
2008	0.947910010814667
2009	0.993879973888397
2011	1.07869005203247
2012	1.07973003387451
2013	1.0633100271225
2014	1.05233001708984
2015	1.07193005084991
2016	1.06729996204376
2017	1.06237995624542
2018	1.02350997924805
2019	0.995700001716614
2020	0.958419978618622
2021	0.91746997833252