Year	gross (GPI)
1999	0.98157000541687
2000	0.966870009899139
2001	0.969399988651276
2002	0.947759985923767
2003	0.931500017642975
2004	0.923409998416901
2005	0.938030004501343
2006	0.955470025539398
2007	0.956110000610352
2008	0.960789978504181
2009	0.971279978752136
2010	0.986959993839264
2011	0.971710026264191
2012	1.02507996559143
2013	0.978100001811981
2014	0.968640029430389
2015	0.964263737201691