Year	gross (GPI)
1970	0.553179979324341
1971	0.553539991378784
1972	0.560949981212616
1973	0.569350004196167
1974	0.567839980125427
1975	0.572839975357056
1976	0.577199995517731
1977	0.5832200050354
1978	0.581610023975372
1979	0.589280009269714
1980	0.593580007553101
1981	0.603980004787445
1982	0.608020007610321
1983	0.621219992637634
1984	0.618430018424988
1985	0.628269970417023
1986	0.645680010318756
1987	0.652869999408722
1988	0.669210016727448
1989	0.668370008468628
1990	0.680130004882813
1991	0.698230028152466
1992	0.709649980068207
1993	0.731060028076172
1994	0.744899988174438
1995	0.749960005283356
1996	0.759649991989136
1997	0.773699998855591
1998	0.786870002746582
1999	0.79925000667572
2000	0.806500017642975
2001	0.81580001115799
2002	0.833779990673065
2003	0.903199970722198
2004	0.897140026092529
2005	0.911329984664917
2006	0.918889999389648
2007	0.930069983005524
2008	0.95048999786377
2009	0.969120025634766
2010	0.970820009708405
2011	0.980570018291473
2012	0.984279990196228
2013	1.03296995162964
2014	1.03259003162384
2015	1.03336000442505
2016	1.05137002468109
2017	1.04560995101929
2018	0.996649980545044
2019	1.00069999694824
2020	0.992489993572235