Year	gross (GPI)
1976	1.02329003810883
1977	1.03700995445251
1978	1.05418002605438
1979	1.05902004241943
1980	1.05765998363495
1982	1.04697000980377
1983	1.01910996437073
1985	1.00896000862122
1986	1.01385998725891
1992	1.00697004795074
1993	1.0195699930191
1995	1.00381994247437
1996	1.03943002223969
1997	1.0053299665451
1998	0.997669994831085
1999	0.967419981956482
2002	0.993900001049042
2004	0.976719975471497
2005	0.969669997692108
2006	0.968930006027222