Year	gross (GPI)
1982	0.954060018062592
1983	0.958809971809387
1984	0.982230007648468
1985	0.961769998073578
1986	0.985189974308014
1987	0.98088002204895
1988	0.984369993209839
1989	1.00268995761871
1990	1.00537002086639
1991	1.00584995746613
1992	0.98335999250412
1993	0.986930012702942
1994	0.963949978351593
1995	0.95048999786377
1997	0.920409977436066