Year	Grams per day
1961	8.28
1962	11.78
1963	8.42
1964	7.27
1965	12.02
1966	10.42
1967	7.71
1968	8.08
1969	8.57
1970	8.63
1971	9.03
1972	8.69
1973	8.29
1974	7.91
1975	8.22
1976	8.91
1977	10.57
1978	12.03
1979	18.22
1980	16.63
1981	15.12
1982	14.02
1983	15.91
1984	22.01
1985	26.78
1986	33.79
1987	32.24
1988	20.19
1989	27.03
1990	24.63
1991	27.11
1992	28.04
1993	27.51
1994	27.04
1995	28.81
1996	29.34
1997	30.52
1998	30.78
1999	30.8
2000	31.22
2001	29.38
2002	28.34
2003	31.06
2004	32.1
2005	35.49
2006	35.58
2007	36.26
2008	37.02
2009	37.76
2010	35.53
2011	35.03
2012	32.68
2013	27.23