Year	gross (GPI)
1971	0.963230013847351
1976	1.07459998130798
1977	1.08416998386383
1978	1.03343999385834
1979	0.995199978351593
1980	0.800840020179749
1981	0.787169992923737
1982	0.800740003585815
1983	0.775950014591217
1984	0.766269981861115
1985	0.776830017566681
1986	0.786339998245239
1987	0.791620016098022
1988	0.799459993839264
1989	0.814869999885559
1990	0.818470001220703
1991	0.823249995708466
1992	0.812839984893799
1999	0.966570019721985
2000	0.894289970397949
2001	0.939040005207062
2002	0.955209970474243
2003	0.877960026264191
2004	0.897830009460449
2005	0.888880014419556
2006	0.90531998872757
2007	0.891269981861115
2008	0.893249988555908
2009	0.937160015106201
2010	1
2011	1.03999996185303
2012	1.07516002655029
2013	1.07623994350433
2014	1.09551000595093
2015	1.08518004417419
2016	1.09850001335144
2017	1.12241005897522
2018	1.12419998645782
2019	1.1319500207901
2021	1.1450400352478