Year	gross (GPI)
1970	0.215650007128716
1971	0.255019992589951
1972	0.261629998683929
1974	0.228670001029968
1975	0.2151899933815
1976	0.241099998354912
1977	0.334369987249374
1979	0.3160600066185
1980	0.28532001376152
1981	0.288919985294342
1982	0.356920003890991
1985	0.291850000619888
1986	0.376080006361008
1988	0.379680007696152
1989	0.366580009460449
1990	0.381949990987778
1991	0.370869994163513
1992	0.390579998493195
1993	0.416700005531311
1994	0.452740013599396
1995	0.473269999027252
1996	0.487150013446808
1999	0.51596999168396
2000	0.50093001127243
2001	0.514670014381409
2002	0.609549999237061
2003	0.587679982185364
2004	0.609489977359772
2006	0.748730003833771
2008	0.781470000743866
2009	0.781849980354309
2010	0.773419976234436
2011	0.764500021934509
2012	0.715250015258789
2013	0.747181236743927
2014	0.76460999250412
2015	0.785156965255737
2016	0.776595771312714