Year	gross (GPI)
1970	1.11257994174957
1971	1.10936999320984
1972	1.09064996242523
1973	1.07462000846863
1974	1.10943996906281
1975	1.10166001319885
1976	1.0862900018692
1977	1.09858000278473
1978	1.103600025177
1979	1.10759997367859
1980	1.12331998348236
1981	1.12388002872467
1982	1.12268996238708
1983	1.12843000888824
1984	1.12578999996185
1985	1.11760997772217
1986	1.12555003166199
1987	1.11266005039215
1988	1.10580003261566
1989	1.09124994277954
1990	1.0742199420929
1999	1.07836997509003
2000	1.06737005710602
2001	1.07427000999451
2002	1.06910002231598
2004	1.07228004932404
2005	1.07016003131866
2006	1.08098995685577
2007	1.0709400177002
2008	1.07602000236511
2009	1.07703995704651
2010	1.06171000003815
2011	1.07450997829437
2013	1.06368005275726
2014	1.07486999034882
2015	1.05427002906799
2016	1.02795004844666
2017	1.05675995349884
2021	1.0391252040863