Year	gross (GPI)
1973	1.02804005146027
1974	1.03076004981995
1975	1.03144001960754
1976	1.03166997432709
1977	1.03615999221802
1978	1.02610003948212
1979	1.00360000133514
1980	0.993040025234222
1981	0.953949987888336
1982	0.950619995594025
1983	0.954079985618591
1984	0.955219984054565
1985	0.937680006027222
1986	0.912800014019012
1987	0.89819997549057
1988	0.892260015010834
1989	0.8994500041008
1990	0.905350029468536
1991	0.904680013656616
1992	0.919860005378723
1993	0.931640028953552
1994	0.92400997877121
1995	0.926540017127991
1996	0.946879982948303
1997	0.971040010452271
1998	0.986810028553009
1999	1.02189004421234
2000	1.04135000705719
2001	1.04934000968933
2002	1.06205999851227
2003	1.0629700422287
2004	1.08448004722595
2005	1.08160996437073
2006	1.10376000404358
2007	1.12405002117157
2008	1.14093995094299
2009	1.15377998352051
2010	1.16552996635437
2011	1.17296004295349
2012	1.17123997211456
2013	1.1745799779892
2014	1.17832005023956
2015	1.18412005901337
2016	1.19668996334076
2017	1.19669997692108
2018	1.20134997367859
2019	1.20248997211456
2020	1.19165003299713
2021	1.18193995952606
2022	1.16823995113373