Year	gross (GPI)
1981	0.824140012264252
1986	0.872780025005341
1991	0.983680009841919
1992	0.974349975585938
1993	0.971520006656647
1994	0.951399981975555
1995	0.956459999084473
1996	0.997979998588562
1997	0.990190029144287
1999	1.01502001285553
2000	1.02469003200531
2001	1.05137002468109
2002	1.04945003986359
2003	1.041100025177
2004	1.03957998752594
2005	1.03953003883362
2006	1.07647001743317
2008	1.01988995075226
2013	1.0081000328064
2014	1.01177000999451
2015	1.01435995101929
2016	1.01025998592377
2017	1.01057004928589
2018	1.01249003410339
2019	1.00751996040344
2020	1.00706994533539
2021	1.00573003292084