Assertion: albatross's number | /r/HasProperty | declined to low levels
Facets:
value: progressively
type: MANNER
value: very
type: DEGREE
Source sentences:
text: Historical data from Australia where Crozet birds were known to spend their sabbatical year in large number during the 1960–1970s21 show that numbers have progressively declined to very low levels due to a reduction in availability of a local food resource49.