Year	gross (GPI)
1971	0.223989993333817
1972	0.259810000658035
1973	0.316969990730286
1974	0.388799995183945
1975	0.450659990310669
1976	0.517880022525787
1977	0.580280005931854
1978	0.644339978694916
1979	0.685490012168884
1980	0.708639979362488
1981	0.694199979305267
1983	0.739170014858246
1986	0.863160014152527
2002	1.06498003005981
2003	1.06518995761871
2005	1.19186997413635
2006	1.17545998096466