Year Grams per day 1961 142.62 1962 143.92 1963 140.74 1964 145.25 1965 147.34 1966 147.18 1967 150.17 1968 151.45 1969 155.18 1970 156.1 1971 158.67 1972 161.28 1973 161.9 1974 157.21 1975 151.85 1976 159.74 1977 163.28 1978 160.16 1979 161.72 1980 157.51 1981 156.1 1982 154.41 1983 155.87 1984 158.89 1985 160.3 1986 161.71 1987 166.88 1988 168.59 1989 168.32 1990 173.28 1991 174.78 1992 177.37 1993 180.6 1994 183.23 1995 182.55 1996 185.99 1997 192.63 1998 194.43 1999 187.94 2000 189.39 2001 186.31 2002 193.4 2003 191.89 2004 194.15 2005 192.85 2006 187.25 2007 174.9 2008 169.61 2009 164.9 2010 166.57 2011 171.66 2012 174.05 2013 174.67