Year Grams per day 1961 36.96 1962 37.54 1963 37.54 1964 38.98 1965 34.83 1966 39 1967 38.53 1968 38.59 1969 35.15 1970 41.3 1971 41.22 1972 44.3 1973 47.55 1974 35.13 1975 27.61 1976 42.49 1977 48.25 1978 48.4 1979 45.27 1980 41.18 1981 31.12 1982 30.5 1983 31.37 1984 29.6 1985 34.18 1986 31 1987 30.43 1988 30.6 1989 32.73 1990 43.78 1991 42.68 1992 41.53 1993 42 1994 44.38 1995 42.6 1996 45.52 1997 39.04 1998 36.74 1999 38.94 2000 42.57 2001 48.55 2002 53.18 2003 52.13 2004 56.93 2005 56.91 2006 58.51 2007 59.56 2008 59.23 2009 60.48 2010 62.12 2011 62.53 2012 35.81 2013 50.52