Hi,
no idea for WolframAlpha, but it seems to be working in the Wolfram Language.
countriespop1994 = {CommonName[#], CountryData[#, {"Population", 1994}]} & /@ CountryData[] //TableForm
The first lines of the output look like this:

If you need that data, you could open up a free (!) WolframCloud account and use the Wolfram language there. For your convenience I have attached the file with the data in csv format
Cheers,
M.
Attachments: