Create query excluding certain census records Seeking to find individuals not having 1939 ceb=nsus event

I wish to create a query to ascertain which individuals potentially should have 1939 census fact but who do not. I can exclude individuals died prior to 1939 and also those born after 1939 but as the census number for the 1939 census may be 1 to 5 or 6 but simple query does not exclude 1939 unless it is the first census. How can I rewrite the qury to just exlude thos who already have a census entry for 1939 Your help would be appreciated