Year	gross (GPI)
1992	0.211799994111061
1997	0.148670002818108
1999	0.273110002279282
2002	0.341809988021851
2003	0.352670013904572
2004	0.370840013027191
2005	0.368209987878799
2006	0.388700008392334
2007	0.417569994926453
2008	0.43529000878334
2010	0.441029995679855
2011	0.444400012493134