CO2 monthly is CO2 expressed as a mole fraction in dry air, micromol/mol, abbreviated as ppm
a record has: year, month,decimal-date, average, interpolated, trend-season-corr, days
For instance: 1958 3 1958.208 315.71 315.71 314.62 -1
CO2 annual has three values
Year, Avg, Uncorrected