Year Grams per day 1961 11.71 1962 12.14 1963 12.96 1964 13.04 1965 18.25 1966 16.7 1967 21.04 1968 21.21 1969 25.01 1970 25.06 1971 25 1972 24.34 1973 26.28 1974 21.34 1975 19.37 1976 19.47 1977 15.95 1978 14.57 1979 17.97 1980 16.15 1981 17.72 1982 15.33 1983 18.66 1984 19.97 1985 21.13 1986 17.59 1987 18.49 1988 15.59 1989 18.57 1990 13.8 1991 15.8 1992 15.08 1993 16.65 1994 21.35 1995 23.66 1996 23.35 1997 24.99 1998 25.31 1999 30.3 2000 35.72 2001 34.44 2002 33.44 2003 34.94 2004 37.86 2005 31.99 2006 35.85 2007 31.69 2008 31.54 2009 26.8 2010 28.72 2011 27.16 2012 29.17 2013 27.36