Year Grams per day 1961 40.73 1962 38.19 1963 35.58 1964 36.36 1965 42.13 1966 46.57 1967 33.62 1968 43.73 1969 46.36 1970 41.96 1971 43.84 1972 43.64 1973 64.88 1974 66.78 1975 63.99 1976 73.26 1977 80.48 1978 84.14 1979 83.7 1980 80.6 1981 78.1 1982 77.92 1983 81.1 1984 73.54 1985 73.8 1986 80.51 1987 80.58 1988 82.89 1989 83 1990 83.92 1991 85.82 1992 77.09 1993 77.24 1994 75.07 1995 74.46 1996 73.45 1997 71.77 1998 74.17 1999 74.5 2000 71.08 2001 69.49 2002 73.73 2003 72.41 2004 72.49 2005 77.6 2006 76.89 2007 81.25 2008 78.99 2009 73.61 2010 78.85 2011 77.96 2012 77.08 2013 81.16