Board Thread:Suggestions forum/@comment-26149161-20170907221858/@comment-26890432-20170909150431

The Black Numenorean population by the end of the Third Age was probably extremely small, likely in the low hundreds, hidden away in Mordor. There were essentially no Black Numenoreans in Umbar: in the centuries preceeding the War of the Ring, they were almost entirely killed off in war or intermingled with the Haradrim. At this time, Umbar was pretty much an entirely Haradric state.

In Gondor, even though the "Common Folk" have lesser Numenorean blood, they are still ruled over by lords that have a good degree of Numenorean ancestry, and perhaps more importantly, still adhere to Numenorean customs. This means that while everyone in Gondor might not have been a Numenorean, the customs, relics, and learning would have been much better preserved than in other areas.