Assertion: coal mine's output | /r/HasProperty | some 6¼ million long tons
Facets:
value: between 1780
type: TEMPORAL
value: between 1770
type: TEMPORAL
Source sentences:
text: Between 1770 and 1780 the annual output of coal was some 6¼ million long tons (or about the output of a week and a half in the 20th century).