Year	gross (GPI)
1978	0.108709998428822
1988	0.149829998612404
1989	0.1511500030756
1990	0.132019996643066
1991	0.168809995055199
1992	0.177349999547005
1993	0.1769700050354
1994	0.211140006780624
1995	0.209380000829697
1996	0.215900003910065
1997	0.186049997806549
1998	0.199279993772507
1999	0.215120002627373
2001	0.206310003995895
2002	0.273550003767014
2003	0.274619996547699
2004	0.310570001602173
2005	0.324270009994507
2006	0.342689990997314
2008	0.387050002813339
2009	0.381309986114502
2010	0.377279996871948
2011	0.38060998916626
2012	0.385390013456345
2013	0.391299992799759
2015	0.446909993886948
2016	0.452939987182617
2017	0.453090012073517
2018	0.490000009536743
2019	0.556060016155243
2020	0.567089974880219