Year	gross (GPI)
1991	0.988009989261627
1992	0.995819985866547
1993	0.979700028896332
1994	0.955860018730164
1995	1.12442994117737
1996	1.08429002761841
1997	0.978860020637512
1998	0.981549978256226
1999	1.00063002109528
2000	0.981610000133514
2001	0.983919978141785
2002	0.975650012493134
2003	0.943490028381348
2004	0.963519990444183
2005	0.945110023021698
2006	0.936280012130737
2007	0.996879994869232
2008	0.994690001010895
2009	0.98922997713089
2010	0.989530026912689
2011	0.980520009994507
2012	0.979770004749298
2013	0.969030022621155
2014	0.990019977092743
2015	0.983179986476898
2016	0.990109980106354
2017	1.0163300037384
2018	1.00546002388
2019	1.03080999851227
2020	1.04425001144409
2021	1.01040995121002