Year	Grams per day
1992	37.38
1993	30.82
1994	32.83
1995	34.97
1996	38.22
1997	41.35
1998	40.79
1999	33.76
2000	29.93
2001	34.96
2002	43.24
2003	44.88
2004	42.63
2005	48.8
2006	50.48
2007	37.05
2008	39.64
2009	39.98
2010	43.36
2011	44.16
2012	48.32
2013	50.46