See the data version history.
The data of old versions are available only if the versions are included in Yearly fixed datasets.

 ¹³CH₄ _ HFD6419 _ surface - insitu _ NPL _ data1

Updated Date	Version † met : with meteorological data	Details
2025-09-10	0154-6419-1101-01-01-9999 -2025-08-01-1511	The latest version