Year Grams per day 1961 146.47 1962 149.58 1963 122.12 1964 139.23 1965 138.15 1966 137.6 1967 133.47 1968 146.74 1969 142.89 1970 146.09 1971 141.87 1972 155.83 1973 138.8 1974 147.4 1975 101.58 1976 118.11 1977 143.18 1978 122.76 1979 125.47 1980 126.88 1981 132.31 1982 123.64 1983 139.24 1984 131.8 1985 128.26 1986 134.7 1987 132.21 1988 143.4 1989 137.26 1990 139.73 1991 123.06 1992 133.84 1993 137.29 1994 123.77 1995 133.33 1996 143.67 1997 141.2 1998 132.52 1999 138.01 2000 149.18 2001 147.33 2002 156.58 2003 155.79 2004 162.79 2005 161.25 2006 164.23 2007 161.52 2008 162.81 2009 159.24 2010 160.87 2011 159.5 2012 165.33 2013 165.51