Year	Grams per day
1992	30.6
1993	29.8
1994	32.47
1995	36.18
1996	39.27
1997	40.59
1998	35.58
1999	35.18
2000	40.42
2001	31.87
2002	35.72
2003	36.96
2004	37.79
2005	38.68
2006	45.06
2007	44.67
2008	47.75
2009	50.26
2010	49.71
2011	51.56
2012	50.59
2013	51.94