Year	gross (GPI)
1970	0.599309980869293
1971	0.666710019111633
1972	0.800890028476715
1973	0.838599979877472
1974	0.89819997549057
1979	0.947019994258881
1980	0.9339399933815
1983	1.00352001190186
1988	1.05277001857758
1989	1.07666003704071
1990	1.09561002254486
1991	1.0638200044632
1992	1.07236003875732
1993	1.09759998321533
1994	1.11556994915009
1998	1.18871998786926
1999	1.20882999897003
2012	1.25911998748779
2013	1.26084005832672
2014	1.26461005210876
2015	1.25118005275726
2016	1.26273000240326
2017	1.25383996963501
2018	1.26388001441956
2019	1.27127003669739
2020	1.30202996730804
2021	1.31643998622894
2022	1.31669998168945