Assertion: butterfly's number | /r/CapableOf | decline by more than 90 percent
Facets:
value: since 1995
type: TEMPORAL
Source sentences:
text: There is increasing concern related to the ongoing decline of monarchs at their overwintering sites; based on a 2014 twenty-year comparison, the overwintering numbers west of the Rocky Mountains have dropped more than 50 percent since 1997 and the overwintering numbers east of the Rockies have declined by more than 90 percent since 1995.