Year Grams per day 1961 101.96 1962 107.4 1963 112.69 1964 105.59 1965 112.56 1966 125.32 1967 123.25 1968 124.98 1969 121.07 1970 118.27 1971 123.26 1972 118.11 1973 128.3 1974 125.66 1975 121.4 1976 125.36 1977 121.61 1978 126.64 1979 140.12 1980 157.02 1981 151.63 1982 140 1983 143.58 1984 145.5 1985 139.25 1986 150.12 1987 155.92 1988 157.96 1989 141.98 1990 147.41 1991 142.74 1992 131.92 1993 136.29 1994 147.09 1995 160.61 1996 169.41 1997 180.25 1998 166.97 1999 165.71 2000 180.05 2001 181.93 2002 161.92 2003 163.04 2004 171.96 2005 170.12 2006 173.95 2007 172.19 2008 171.32 2009 171.2 2010 156.84 2011 156.62 2012 160.73 2013 161.67