Assertion: coccyx | /r/HasProperty | complete
Facets:
value: by the age of 30
type: TEMPORAL
value: usually
type: DEGREE
Source sentences:
text: The last three to five (usually four) vertebrae of the spinal column are fused together to make the coccyx, colloquially known as the tailbone.﻿﻿ Fusion begins during a person's 20s and is usually complete by the age of 30.