Year	gross (GPI)
1971	0.792209982872009
1972	0.841620028018951
1973	0.839489996433258
1974	0.842029988765717
1975	0.843990027904511
1976	0.860300004482269
1977	0.863170027732849
1978	0.863240003585815
1979	0.8785600066185
1980	0.895039975643158
1981	0.898389995098114
1982	0.9200199842453
1983	0.932449996471405
1984	0.936699986457825
1985	0.935739994049072
1986	0.933470010757446
1987	0.921739995479584
1988	0.92509001493454
1989	0.932479977607727
1990	0.949000000953674
1992	0.993820011615753
1993	1.00636005401611
1994	1.01822996139526
1995	1.04271996021271
1996	1.02163994312286
1997	1.01552999019623
1998	1.01242995262146
1999	1.00271999835968
2000	1.0181599855423
2001	1.0372200012207
2003	1.06288003921509
2004	1.07216000556946
2005	1.06889998912811
2006	1.03978002071381
2007	1.01240003108978
2008	1.02132999897003
2009	1.00905001163483
2010	1.00117003917694
2011	0.987240016460419
2012	1.0372200012207
2013	1.03312003612518
2014	1.03731000423431
2015	1.04884004592896