Year	gross (GPI)
1981	1.03886997699738
1982	1.03232002258301
1983	1.02068996429443
1984	1.02276003360748
1985	1.02069997787476
1986	1.0229400396347
1987	1.01155996322632
1990	0.997739970684052
1991	0.99838000535965
1993	0.988919973373413
1994	0.991439998149872
1995	1.00136005878448
1996	0.993629992008209
1998	1.03120994567871
2005	1.00387001037598
2013	0.997099995613098
2014	1.00423002243042
2015	1.00507998466492
2016	0.996259987354279
2017	0.993629992008209
2018	0.994700014591217
2019	0.994910001754761
2020	0.986829996109009