Year	Grams per day
1961	5.05
1962	4.06
1963	9.48
1964	7.88
1965	7.64
1966	7.09
1967	6.24
1968	6.12
1969	6.88
1970	6.43
1971	8.13
1972	11.55
1973	14.49
1974	12.57
1975	17.49
1976	15.64
1977	17.79
1978	19.46
1979	21.34
1980	24.27
1981	22.41
1982	21.07
1983	25.51
1984	25.82
1985	26.39
1986	23.96
1987	23.82
1988	25.08
1989	25.94
1990	26.48
1991	25.11
1992	18.61
1993	17.95
1994	20.43
1995	22.35
1996	21.45
1997	17.01
1998	23.44
1999	24.45
2000	27.29
2001	31.84
2002	34.77
2003	37.22
2004	41.24
2005	39.83
2006	42.07
2007	51.93
2008	52
2009	38.63
2010	37.11
2011	38.32
2012	41.85
2013	48.37