Year	gross (GPI)
1992	0.970290005207062
1993	0.958469986915588
1994	0.963460028171539
1995	0.964529991149902
1996	0.967620015144348
1997	0.971509993076324
1998	0.970990002155304
1999	0.974690020084381
2000	0.979420006275177
2001	0.980310022830963
2002	0.978829979896545
2003	0.975199997425079
2004	0.975340008735657
2005	0.974219977855682
2006	0.971080005168915
2007	0.97408002614975
2008	0.972010016441345
2009	0.947019994258881
2010	0.948310017585754
2011	0.947080016136169
2012	0.947420001029968
2013	0.952759981155396
2014	0.953149974346161
2015	0.953170001506805
2016	0.949079990386963
2017	0.939220011234283
2018	0.941559970378876
2019	0.947109997272491
2020	0.953830003738403