Year	gross (GPI)
1971	0.466659992933273
1973	0.385120004415512
1976	1.08429002761841
1977	0.567170023918152
1978	0.531189978122711
1979	0.499610006809235
1986	0.633660018444061
1987	0.701619982719421
1989	0.766969978809357
1990	0.784979999065399
1991	0.827939987182617
1994	0.78982001543045
1995	0.847299993038177
1996	0.827160000801086
1997	0.829089999198914
1998	0.846130013465881
1999	0.854380011558533
2000	0.877219974994659
2001	0.849969983100891
2002	0.845860004425049
2003	0.846750020980835
2004	0.916249990463257
2005	0.906029999256134
2006	0.887610018253326
2007	0.9028599858284
2008	0.911450028419495
2009	0.921980023384094
2010	0.931249976158142
2011	0.9480100274086
2012	0.938489973545074
2013	0.959789991378784
2014	0.939790010452271
2015	0.925249993801117
2016	0.940880000591278
2017	0.951129972934723
2018	0.969060003757477
2019	0.983650028705597
2020	0.984650015830994
2021	0.98365318775177
2022	1.01875996589661