Year	gross (GPI)
1977	0.364560008049011
1978	0.374469995498657
1979	0.385500013828278
1980	0.407579988241196
1981	0.433349996805191
1982	0.454070001840591
1983	0.481110006570816
1984	0.49371001124382
1985	0.477829992771149
1986	0.4860700070858
1987	0.485920011997223
1988	0.475479990243912
1989	0.494100004434586
1990	0.526920020580292
1991	0.537760019302368
1992	0.544560015201569
1993	0.562560021877289
1994	0.581260025501251
1995	0.595300018787384
1996	0.605589985847473
1998	0.70414000749588
1999	0.72639000415802
2000	0.753260016441345
2001	0.756389975547791
2002	0.773329973220825
2003	0.801090002059937
2004	0.824240028858185
2005	0.865649998188019
2006	0.900789976119995
2007	0.924700021743774
2008	0.992410004138947
2009	1.01130998134613
2010	0.989430010318756
2011	1.00019001960754
2012	1.00308001041412
2013	1.01347005367279
2014	1.014279961586
2015	1.03004002571106
2016	1.02540004253387
2017	1.04795002937317
2018	1.05497002601624
2019	1.06560003757477
2020	1.0848799943924
2021	1.10327994823456
2022	1.11602997779846