Year	gross (GPI)
1992	0.965550005435944
1993	0.964049994945526
1994	0.966449975967407
1995	0.964200019836426
1996	0.967369973659515
1997	0.970749974250793
1998	0.963760018348694
1999	0.957859992980957
2000	0.961740016937256
2001	0.952759981155396
2002	0.949500024318695
2003	0.942740023136139
2004	0.947250008583069
2005	0.950519979000092
2006	0.956499993801117
2007	0.958670020103455
2008	0.964010000228882
2009	0.972339987754822
2010	0.969529986381531
2011	0.967830002307892
2012	0.976230025291443
2013	0.98063999414444
2014	0.981549978256226
2015	0.982640027999878
2016	0.984340012073517
2017	0.974629998207092
2018	0.981190025806427
2019	0.978450000286102
2020	0.981809973716736