Year	gross (GPI)
1970	0.852989971637726
1971	0.894200026988983
1972	0.874790012836456
1973	0.876940011978149
1974	0.872720003128052
1975	0.869939982891083
1976	0.892570018768311
1977	0.912679970264435
1978	0.906970024108887
1979	0.913839995861053
1980	0.936619997024536
1981	0.932269990444183
1982	0.945930004119873
1983	0.959540009498596
1984	0.965950012207031
1985	0.990800023078918
1986	1.01260995864868
1987	1.02371001243591
1988	1.04210996627808
1989	1.0532900094986
1990	1.06066000461578
1991	1.06482005119324
1992	1.08289003372192
1993	1.08212995529175
1994	1.10931003093719
1995	1.150750041008
1996	1.16396999359131
1997	1.17374002933502
1998	1.2148300409317
1999	1.22664999961853
2000	1.25586998462677
2001	1.28584003448486
2002	1.30923998355865
2003	1.29929995536804
2004	1.29053997993469
2005	1.2929300069809
2006	1.28473997116089
2007	1.29404997825623
2008	1.29413998126984
2009	1.29015004634857
2010	1.29483997821808
2011	1.2878600358963
2012	1.30543994903564
2013	1.31547999382019
2014	1.31339001655579
2015	1.32480001449585
2016	1.33395004272461
2017	1.35012996196747
2018	1.35032999515533
2019	1.34586000442505
2020	1.34520995616913
2021	1.33504998683929