Year	gross (GPI)
1981	0.976469993591309
1986	0.972299993038177
1991	1.00071001052856
1992	0.977219998836517
1993	0.951460003852844
1994	0.930249989032745
1995	1.02050995826721
1996	1.04154002666473
1997	1.07888996601105
2018	1.00118005275726
2019	0.997759997844696
2020	0.980109989643097
2021	0.983489990234375