Year	gross (GPI)
1989	1.00284004211426
1990	1.06893002986908
1991	0.997820019721985
1992	1.00753998756409
1993	1.00775003433228
1994	0.997889995574951
1995	0.971949994564056
1996	0.970979988574982
1997	0.970960021018982
1998	0.975669980049133
1999	0.976530015468597
2000	0.979589998722076
2001	0.976629972457886
2002	0.972729980945587
2003	0.970120012760162
2004	0.972679972648621
2005	0.976279973983765
2006	0.977980017662048
2007	0.967140018939972
2008	0.966080009937286
2009	0.970659971237183
2010	0.980849981307983
2011	0.985329985618591
2012	0.99015998840332
2013	0.993629992008209
2014	0.998510003089905
2015	1.00073003768921
2016	1.00077998638153
2017	1.00192999839783
2018	1.00484001636505
2019	1.00041997432709
2020	1.00128996372223