Assertion: urban area's rate | /r/HasProperty | three-fold
Facets:
value: to around 438 in 2005
type: TEMPORAL
value: around 160 in 1975
type: TEMPORAL
value: in every three decades
type: TEMPORAL
Source sentences:
text: The rate of increase in the number of million cities has been three-fold in every three decades – around 160 in 1975 to around 438 in 2005.