Year	gross (GPI)
1971	0.885200023651123
1972	0.99888002872467
1973	1.06421005725861
1974	1.10564005374908
1975	1.15768003463745
1976	1.1515200138092
1977	1.0983099937439
1978	1.07946002483368
1979	1.05072999000549
1980	1.04053997993469
1981	1.03939998149872
1982	0.982739984989166
1983	0.967890024185181
1984	0.957170009613037
1985	0.958280026912689
1986	0.951250016689301
1987	1.0531200170517
1988	1.05097997188568
1989	1.06013000011444
1990	1.05467998981476
1991	1.03637003898621
1992	1.03562998771667
1993	1.03178000450134
1994	0.998769998550415
1995	0.983269989490509
1996	0.989449977874756
1998	0.980149984359741
1999	1.02627003192902
2000	1.03357994556427
2001	1.06112003326416
2002	0.996140003204346
2003	0.944350004196167
2004	0.904500007629395
2005	0.940699994564056
2006	1.0351300239563
2010	0.996550023555756