Year	Grams per day
1961	3.91
1962	3.89
1963	6.15
1964	7
1965	7.37
1966	7.5
1967	7.06
1968	9.22
1969	10.98
1970	11.65
1971	12.84
1972	13.21
1973	12.69
1974	8.71
1975	7.84
1976	7.38
1977	6.25
1978	9.56
1979	5.08
1980	8.66
1981	9.46
1982	6.48
1983	6.61
1984	6.48
1985	8.84
1986	8.31
1987	5.49
1988	9.04
1989	8.88
1990	5.6
1991	6.46
1992	4.93
1993	5.1
1994	10.14
1995	6.24
1996	14.28
1997	16.81
1998	9.93
1999	12.65
2000	13.89
2001	18.05
2002	14.28
2003	19.22
2004	30.27
2005	29.86
2006	29.12
2007	30.04
2008	29.1
2009	28.69
2010	29.75
2011	29.93
2012	28.69
2013	30.29