Year	gross (GPI)
1970	1.48084998130798
1972	1.47798001766205
1973	1.46401000022888
1974	1.46398997306824
1975	1.43308997154236
1976	1.42495000362396
1977	1.44142997264862
1978	1.45624005794525
1979	1.4388200044632
1980	1.41147994995117
1981	1.37215995788574
1982	1.32841002941132
1983	1.30209004878998
1984	1.27191996574402
1985	1.2567800283432
1986	1.24266004562378
1987	1.23714995384216
1988	1.2243800163269
1989	1.21088004112244
1990	1.20956003665924
1991	1.20512998104095
1992	1.17706000804901
1993	1.15669000148773
1994	1.13277995586395
1995	1.10922002792358
1996	1.11155998706818
1997	1.09390997886658
1998	1.08606994152069
1999	1.07798004150391
2000	1.03339004516602
2001	1.01138997077942
2002	1.00442004203796
2003	1.00269997119904
2004	0.99058997631073
2005	0.987779974937439
2006	0.985329985618591
2007	0.977199971675873
2008	0.974129974842072
2009	0.978839993476868
2010	0.957780003547668
2011	0.950649976730347
2012	0.955359995365143
2013	0.961409986019135
2014	0.957130014896393
2015	0.950119972229004
2016	0.950150012969971
2017	0.949289977550507
2018	0.950330018997192
2019	0.951355755329132