Year	gross (GPI)
1975	1.01529002189636
1976	1.00437998771667
1979	1.03933000564575
1980	1.01786005496979
1983	1.05292999744415
1991	1.06164002418518
1993	1.1517299413681
1994	1.19213998317719
1995	1.19569003582001
1996	1.17756998538971
1997	1.1657999753952
1998	1.15455996990204
1999	1.12480998039246
2000	1.11673998832703
2001	1.11354994773865
2002	1.10487997531891
2003	1.08103001117706
2004	1.06400001049042
2005	1.06137001514435
2006	1.05493998527527
2009	1.03253996372223
2010	1.02402997016907
2019	0.99260002374649
2020	0.999824345111847
2021	0.99825781583786