Year Grams per day 1961 100.45 1962 109.38 1963 118.21 1964 113.06 1965 137.05 1966 137.77 1967 143.29 1968 143.82 1969 139.27 1970 138.77 1971 140.72 1972 136.97 1973 143.58 1974 140.59 1975 135.94 1976 144.19 1977 142.68 1978 151.21 1979 144.53 1980 144.38 1981 138.89 1982 142.62 1983 144.52 1984 134.63 1985 138.89 1986 135.7 1987 143.46 1988 142.21 1989 140.95 1990 130.16 1991 130.87 1992 133.05 1993 132.52 1994 135.21 1995 140.57 1996 141.59 1997 142.31 1998 139.81 1999 144.77 2000 135.11 2001 141.71 2002 143.77 2003 147.49 2004 149.66 2005 149.27 2006 136.78 2007 137.37 2008 161.9 2009 174 2010 170.73 2011 164.66 2012 167.55 2013 167.95