First time on this forum and first topic. Please correct me if this is not the right place or way to ask this question. I’m still a rookie on OSM as well.
These are the first reliable statistics since 2011 Census. Can we use this public data in OSM or WikiData? I’m really fond of improving the Namibian OSM. Please learn me the basics of using public data and how to tag them correctly.
In general it is okay to use public data. It is important to make sure that you are allowed to use the data for OSM purposes.
The best way is to contact the Namibia Statistics Agency and ask them for their consent.
You should mention this data source in your change set.
edit: If these are the preliminary results, it may be wise to wait for the final numbers. But of course you can ask already.