The Ottoman cadastral tax census (defter) of 1455 in the Branković District (covering most of present-day Kosovo) recorded:
Yugoslav and Serbian scholars have researched the defter, concluding that:
Out of all names mentioned in this census, conducted by the Ottomans in 1455, covering areas of most of present-day Kosovo, 95.88% of all names were of Serbian origin, 1.90% of Roman origin, 1.56% of uncertain origin, 0.26% of Albanian origin, 0.25% of Greek origin, etc.
References
1455 defter of the Branković lands Wikipedia(Text) CC BY-SA