Assertion: lemming's population | /r/CapableOf | peak about every 4 years
Facets:
value: usually
type: DEGREE
Source sentences:
text: Lemming populations rise and fall dramatically, usually peaking about every 4 years and then dropping almost to extinction.
text: For unknown reasons, lemming populations fluctuate drastically, peaking about every four years and then crashing almost to extinction.