Year	Grams per day
1961	4.32
1962	4.53
1963	4.46
1964	5.18
1965	5.88
1966	6.43
1967	7.54
1968	7.4
1969	9.77
1970	11.36
1971	11.97
1972	12.17
1973	12.49
1974	14.98
1975	14.25
1976	14.64
1977	16.91
1978	17.23
1979	18.8
1980	19.74
1981	20.37
1982	19.01
1983	19.69
1984	13.91
1985	13.78
1986	15.88
1987	16.98
1988	16.88
1989	15.6
1990	18.08
1991	17.38
1992	18.34
1993	18.81
1994	17.5
1995	18.28
1996	19.2
1997	24.87
1998	20.62
1999	19.31
2000	24.09
2001	24.64
2002	29.29
2003	27.31
2004	26.84
2005	25.55
2006	23.53
2007	27.36
2008	26.18
2009	21.47
2010	26.38
2011	27.03
2012	25.86
2013	27.23