Year	Grams per day
1961	6.27
1962	8.33
1963	7.73
1964	7.83
1965	8.03
1966	6.24
1967	6.12
1968	6.3
1969	6.99
1970	7.48
1971	7.62
1972	7.92
1973	8.16
1974	8.12
1975	8.45
1976	8.94
1977	9.79
1978	10.42
1979	11.53
1980	10.97
1981	10.67
1982	15.21
1983	18.22
1984	19.98
1985	18.71
1986	18.98
1987	18.9
1988	17.42
1989	17.07
1990	15.3
1991	12.05
1992	10
1993	9.61
1994	7.75
1995	16.46
1996	16.47
1997	18.51
1998	18.87
1999	17.3
2000	18.48
2001	15.81
2002	14.44
2003	17.29
2004	19.57
2005	18.8
2006	17.46
2007	15.79
2008	15.25
2009	18.35
2010	13.31
2011	13.33
2012	13.07
2013	14.54