Year	gross (GPI)
1971	0.796280026435852
1972	0.817300021648407
1976	0.860459983348846
1977	0.85521000623703
1978	0.865390002727509
1986	0.903140008449554
1987	0.898859977722168
1988	0.904659986495972
1989	0.91185998916626
1990	0.920029997825623
1991	0.938470005989075
1992	0.942569971084595
1993	0.942019999027252
1994	0.947939991950989
1999	0.967419981956482
2000	0.993080019950867
2001	0.961210012435913
2002	0.964699983596802
2003	0.967809975147247
2004	0.966489970684052
2005	0.986660003662109
2006	0.982299983501434
2009	0.991249978542328
2010	1.00769996643066
2014	0.988409996032715
2016	1.01693999767303
2017	1.00469994544983
2018	1.01078999042511