Looks like it’s closer to 6% [1]. A lot of people self-diagnose wool allergies, but they really just get crappy wool, or they mistake itchiness caused by the coarseness of the material for an allergy. It’s an easy mistake to make, but it’s unfair to call it an allergy.

[1] https://www.ncbi.nlm.nih.gov/m/pubmed/23665833/