dear，
in the database, there are only data between 2013 and 2018. But in the data density of data source from the atlas, there are data in 1899 in the observation table.
what is wrong? thank you very much
I’m not sure if it’s showing you the observation or observation_period table, but did you check your CDM tables: Whats the MIN(observation_period_start_date) and MIN(observation_date) in those tables?
This is observation, not observation period. From my experience you may have some historical data captured there