Premise: In the past two decades, global fertility has dropped by 1.5 children per woman and industrialized nations have fallen below the 2.1 children-per-woman replacement rate.

Hypothesis: Global fertiity had dropped by 1.5 children per woman and industrialized nations have fallen below the 2.1 children-per-woman replacement rate, all this happened in the past two decades.
Relation: entailment