ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/co2_mm_mlo.txt
# decimal average interpolated trend #days
# date (season corr)
YEAR..MONTH.....AVERAGE CO2 DENSITY
1958 3 ..............................315.71
1959 3 ..............................316.71
1960 3 ..............................317.58
1961 3 ..............................318.54
1962 3 ..............................319.68
1963 3 ..............................319.86
1964 3 ..............................320.76
1965 2 ...............................320.44
1966 3 ..............................322.39
1967 3 ...............................323.04
1968 3 ..............................323.89
1969 3 ..............................325.64
1970 3 ..............................326.87
1971 3 ..............................327.18
1972 3 ..............................327.75
1973 3 ..............................330.30
1974 3 ..............................331.48
1975 3 ..............................331.85
1976 3 ..............................333.46
1977 3 ..............................334.97
1978 3 ..............................336.61
1979 3 ..............................338.13
1980 3 ..............................340.04
1981 3 ..............................341.57
1982 2 .............................341.69
1983 3 .............................343.45
1984 3 ............................345.29
1985 3 ............................347.49
1986 3 ............................347.88
1987 3 ............................349.56
1988 3 ............................352.22
1989 3 ............................353.64
1990 3 ............................355.49
1991 3 ............................357.00
1992 3 ............................357.73
1993 3 ............................358.26
1994 3 ............................359.67
1995 3 ............................361.60
1996 3 ...........................363.91
1997 3 ...........................364.25
1998 3 ...........................366.95
1999 3 ...........................369.46
2000 3 ..........................370.38
2001 3 ..........................372.39
2002 3 ..........................373.87
2003 3 ..........................376.51
2004 3 .........................378.88
2005 3 .........................380.91
2006 3 .........................382.65
2007 3 .........................384.42
2008 3 .........................385.96
2009 3 .........................388.77
2010 3 .........................391.06