Year	Grams per day
1961	18.17
1962	18.87
1963	19.15
1964	21.44
1965	21.46
1966	21.55
1967	22.37
1968	22.12
1969	25.02
1970	25.99
1971	30.77
1972	32.53
1973	34.35
1974	34.67
1975	35.09
1976	34.51
1977	34.32
1978	34.15
1979	33.31
1980	31.21
1981	29.86
1982	27.31
1983	17.55
1984	16.31
1985	7.27
1986	9.13
1987	11.57
1988	11.31
1989	8.87
1990	9.86
1991	9.33
1992	11.49
1993	13.85
1994	16.04
1995	15.42
1996	14.99
1997	15.42
1998	15.82
1999	16.61
2000	20.77
2001	21.04
2002	20.35
2003	23.35
2004	23.34
2005	23.97
2006	23.61
2007	27.75
2008	30.57
2009	31.32
2010	30.67
2011	31.31
2012	29.4
2013	30.74