Year	Grams per day
1992	62.37
1993	45.82
1994	42.2
1995	40.81
1996	46.83
1997	43.46
1998	44.53
1999	36.6
2000	30.57
2001	28.85
2002	28.03
2003	26.55
2004	25.21
2005	24.85
2006	25.11
2007	23.07
2008	24.67
2009	22.14
2010	22.8
2011	25.63
2012	26.62
2013	24.56