I wouldn't take much notice of any trace region under 15%
From Ancestry FAQs page
https://www.ancestry.co.uk/dna/legal/faq#about-2"4. What does it mean when my ethnicity results identify 'Trace Regions'?
Most people may have a percentage identified with 'Trace Regions' in their genetic ethnicity results. Trace Regions are regions where the estimated range includes zero and does not go above 15%, or where the predicted percentage is less than 4.5%. Since there is only a small amount of evidence that you have genetic ethnicity from these regions, it is possible that you may not have genetic ethnicity from them at all. This is not uncommon, and as more genetic signatures are discovered with a higher confidence level, we may be able to update these Trace Regions over time."
