Assertion: porpoise's lifespan | /r/HasProperty | 15 to 20 years
Facets:
value: generally
type: DEGREE
Source sentences:
text: These cetaceans can live up to 22 years, but their lifespan is generally 15 to 20 years.
text: The average lifespan of a cow is between 15-20 years, although cattle raised for dairy and meat do not reach anywhere near that age.