Year	gross (GPI)
1971	0.672599971294403
1972	0.791400015354156
1973	0.925059974193573
1974	1.1523699760437
1975	1.20097005367279
1976	1.38723003864288
1977	1.23611998558044
1978	1.20802998542786
1979	1.15007996559143
1980	1.17967998981476
1981	1.12849998474121
1982	1.07966995239258
1983	1.0212299823761
1984	0.975170016288757
1985	0.943000018596649
1986	0.942969977855682
1987	1.23231995105743
1988	1.20998001098633
1989	1.25801002979279
1990	1.27244997024536
1991	1.20065999031067
1992	1.1910400390625
1993	1.12038004398346
1994	1.03238999843597
1995	0.969110012054443
1996	0.938399970531464
1998	1.06038999557495
1999	1.08122003078461
2000	1.07257997989655
2001	1.10741996765137
2002	1.06545996665955
2003	0.981610000133514
2004	0.899839997291565
2005	0.924539983272552
2006	1.01148998737335
2010	0.948870003223419