Year	gross (GPI)
1971	0.850109994411469
1972	0.864589989185333
1973	0.88358998298645
1974	0.897639989852905
1975	0.911939978599548
1976	0.929099977016449
1977	0.945670008659363
1978	0.959070026874542
1979	0.979250013828278
1980	0.99864000082016
1981	1.01124000549316
1982	1.01084995269775
1983	1.02568995952606
1984	1.02557003498077
1985	1.05236005783081
1986	1.00540995597839
1987	1.01232004165649
1988	1.03545999526978
1989	1.00691998004913
1990	1.00181996822357
1991	1.00592994689941
1992	1.0144100189209
1993	1.01203000545502
1994	1.01336002349854
1995	1.00557005405426
1996	1.01403999328613
1998	1.00778996944427
1999	1.01206004619598
2000	1.01051998138428
2002	1.00637996196747
2003	1.00955998897552
2004	1.01001000404358
2005	1.01041996479034
2006	1.02340996265411
2007	1.01991999149323
2008	1.00379002094269
2010	0.980849981307983
2011	0.977410018444061
2012	0.969829976558685
2013	0.978969991207123
2014	0.989279985427856
2016	0.984210014343262
2017	0.981679975986481
2018	0.981930017471313
2019	0.983349978923798
2020	0.987240016460419
2021	0.987789988517761