Year Grams per day 1961 65.03 1962 66.9 1963 64.93 1964 67.07 1965 64.71 1966 61.96 1967 61.86 1968 62.76 1969 62.43 1970 63.1 1971 63.6 1972 64.7 1973 67.76 1974 66.97 1975 66.28 1976 68.38 1977 67.86 1978 69.81 1979 72.86 1980 69.44 1981 65.97 1982 65.12 1983 68.44 1984 57.41 1985 51.53 1986 47.2 1987 42.36 1988 40.14 1989 43.22 1990 45.02 1991 52.63 1992 50.44 1993 45.26 1994 43.59 1995 55.96 1996 51.71 1997 50.85 1998 53.37 1999 65.63 2000 60.09 2001 60.94 2002 63.85 2003 58.58 2004 60.79 2005 60.12 2006 60.28 2007 59.71 2008 58.66 2009 56.61 2010 47.91 2011 49.45 2012 51.05 2013 45.78