Year	Grams per day
1961	3.52
1962	3.3
1963	4.54
1964	4.71
1965	4.69
1966	4.54
1967	18.89
1968	26.74
1969	31.93
1970	34.7
1971	34.72
1972	32.16
1973	28.44
1974	22.76
1975	21.04
1976	21.53
1977	22.74
1978	24.24
1979	17.36
1980	18
1981	17.07
1982	18.3
1983	16.37
1984	16.11
1985	15.86
1986	13.91
1987	14.6
1988	13.29
1989	12.12
1990	11.21
1991	12.69
1992	11.43
1993	13.08
1994	9.64
1995	6.42
1996	5.95
1997	5.89
1998	4.71
1999	6.71
2000	7.31
2001	7.93
2002	7.5
2003	8.51
2004	8.33
2005	6.42
2006	7.36
2007	13.43
2008	15.49
2009	13.48
2010	12.91
2011	11.36
2012	10.82
2013	10.77