Year	Grams per day
1961	8.28
1962	8.63
1963	9.3
1964	9.15
1965	9.25
1966	10.99
1967	15.02
1968	12.62
1969	13.21
1970	13.72
1971	13.42
1972	10.81
1973	11.38
1974	11.19
1975	10.06
1976	10.04
1977	10.53
1978	11.26
1979	11.2
1980	10.26
1981	10.45
1982	10.74
1983	9.16
1984	8.67
1985	10.97
1986	11.87
1987	12.36
1988	17.69
1989	17.58
1990	19.7
1991	17.1
1992	17.73
1993	16.73
1994	20.39
1995	21.38
1996	16.99
1997	24.11
1998	24.38
1999	20.86
2000	27.7
2001	21.35
2002	21.33
2003	26.21
2004	28.22
2005	28.54
2006	24.02
2007	25.71
2008	25.66
2009	24.62
2010	23.32
2011	24.15
2012	25.68
2013	22.45