Year	Grams per day
1961	17.68
1962	17.14
1963	14.63
1964	16.5
1965	18.12
1966	22.06
1967	21.51
1968	22.74
1969	22.96
1970	21.89
1971	26.52
1972	22.06
1973	22.39
1974	23.82
1975	15.6
1976	18.3
1977	22.22
1978	22.93
1979	28.47
1980	22.28
1981	23.21
1982	21.13
1983	24.94
1984	30.22
1985	24.08
1986	29.59
1987	28.39
1988	27.51
1989	23.4
1990	27.23
1991	18.92
1992	22.15
1993	24.12
1994	26.43
1995	17.61
1996	23.33
1997	23.26
1998	22.41
1999	23.46
2000	17.86
2001	17.93
2002	19.48
2003	22.58
2004	23.05
2005	28.35
2006	36.91
2007	22.37
2008	36.47
2009	29.16
2010	35.79
2011	24.07
2012	15.51
2013	13.14