Year	gross (GPI)
1998	1.00998997688293
2008	0.977240025997162
2009	0.976459980010986
2010	0.977400004863739
2011	0.97749000787735
2012	0.976570010185242
2013	0.984350025653839
2014	0.988839983940125
2015	0.991069972515106
2016	0.991010010242462
2017	0.988579988479614
2018	0.99057000875473
2019	0.992380023002625
2020	0.991100013256073
2021	0.99277001619339