Year	Grams per day
1961	22.2
1962	22.6
1963	19.7
1964	17.79
1965	22.28
1966	24.16
1967	21.3
1968	23.28
1969	22.83
1970	23.57
1971	22.59
1972	21.3
1973	21.48
1974	21.87
1975	19.42
1976	20.04
1977	20.9
1978	22.19
1979	21.62
1980	27.2
1981	27.35
1982	28.66
1983	28.69
1984	26.18
1985	27.91
1986	32.61
1987	31.79
1988	33.36
1989	31.72
1990	28.45
1991	28.88
1992	29.89
1993	28.81
1994	28.43
1995	27.17
1996	24.34
1997	23.89
1998	25.37
1999	24.76
2000	22.28
2001	23.17
2002	28.42
2003	29.12
2004	27.25
2005	27.29
2006	26.58
2007	28.26
2008	27.57
2009	25.19
2010	27.15
2011	28.67
2012	25.56
2013	28.16