Year	gross (GPI)
1992	0.969359993934631
1993	0.969659984111786
1994	0.970269978046417
1995	0.968550026416779
1996	0.969290018081665
1997	0.970910012722015
1998	0.965889990329742
1999	0.962189972400665
2000	0.964060008525848
2001	0.959219992160797
2002	0.957849979400635
2003	0.954779982566834
2004	0.959219992160797
2005	0.961430013179779
2006	0.966489970684052
2007	0.9685999751091
2008	0.973119974136353
2009	0.979480028152466
2010	0.978779971599579
2011	0.978500008583069
2012	0.983380019664764
2013	0.986819982528687
2014	0.988210022449493
2015	0.988839983940125
2016	0.989719986915588
2017	0.9826700091362
2018	0.985979974269867
2019	0.984489977359772
2020	0.986159980297089