Year	gross (GPI)
1971	0.508090019226074
1972	0.5208899974823
1973	0.543439984321594
1974	0.569310009479523
1975	0.581979990005493
1976	0.586579978466034
1977	0.583010017871857
1978	0.577579975128174
1979	0.578819990158081
1980	0.595239996910095
1981	0.596140027046204
1982	0.612760007381439
1983	0.81129002571106
1984	0.821129977703094
1985	0.833679974079132
1986	0.858129978179932
1987	0.882009983062744
1988	0.892920017242432
1989	0.902719974517822
1990	0.934480011463165
1991	0.956789970397949
1992	0.975260019302368
1993	1.00591003894806
1994	1.02236998081207
1995	1.05505001544952
1996	1.03486001491547
1997	1.08307003974915
1998	1.1143399477005
1999	1.13056004047394
2000	1.15568995475769
2001	1.17806994915009
2002	1.2038300037384
2003	1.22834002971649
2004	1.26681995391846
2005	1.26968002319336
2006	1.26839005947113
2007	1.26443004608154
2008	1.26222002506256
2009	1.25293004512787
2010	1.24590003490448
2011	1.2476099729538
2012	1.24986004829407
2013	1.24583995342255
2014	1.24458003044128
2015	1.25510001182556
2016	1.26730000972748
2017	1.27810001373291
2018	1.28269994258881
2019	1.28522002696991
2020	1.27724003791809
2021	1.26323997974396
2022	1.28293001651764