Year	gross (GPI)
1981	0.493000000715256
1987	0.617229998111725
1988	0.647220015525818
1989	0.650189995765686
1990	0.667689979076386
1991	0.692619979381561
1992	0.725369989871979
1993	0.760190010070801
1994	0.784150004386902
1995	0.793280005455017
1996	0.805260002613068
1997	0.847699999809265
1998	0.905759990215302
1999	0.924860000610352
2000	0.927609980106354
2001	0.92451000213623
2002	0.945209980010986
2003	0.96603000164032
2004	0.981299996376038
2005	1.00335001945496
2006	0.990800023078918
2008	1.01476001739502
2009	1.00959002971649
2010	1.01051998138428
2011	1.01251995563507
2012	1.00434994697571
2013	1.02192997932434
2014	1.02126002311707
2015	1.0207200050354
2016	1.03876996040344
2017	1.05054998397827
2018	1.04680001735687
2019	1.06043004989624
2020	1.06951999664307