Year Grams per day 1961 8.21 1962 13.28 1963 28.6 1964 52.66 1965 53.82 1966 52.27 1967 50.8 1968 48.14 1969 45.59 1970 33.79 1971 36.21 1972 41.29 1973 45.86 1974 38.96 1975 39.27 1976 39.19 1977 53.41 1978 53.87 1979 54.32 1980 63.47 1981 57.61 1982 62.01 1983 55.59 1984 56.55 1985 52.73 1986 63.35 1987 58.63 1988 60.87 1989 60.94 1990 64.95 1991 48.48 1992 28.97 1993 34.88 1994 32.65 1995 27.24 1996 28.04 1997 31.31 1998 30.18 1999 25.86 2000 33.21 2001 36.04 2002 32.2 2003 32.34 2004 33.31 2005 37.01 2006 36.68 2007 34.17 2008 39.17 2009 36.36 2010 35.69 2011 39.83 2012 40.89 2013 40.26