어 줄다

drop, shrink, go down in amount

줄다 means a quantity gets smaller on its own — nobody is named as reducing it (that would be 줄이다, the transitive twin). All four example lines are the same past-tense shape reporting a fall: 무려 37%가 줄었습니다 'it dropped by a full 37%'. We are hedging here because that is all the examples show: four near-identical figure-plus-줄었다 lines, with no case of a verb actually pairing with 줄다 through -어, so we cannot tell you what the two-part heading would add.

Register: reporting style

The examples below did not fully pin this one down — read them before relying on the entry above.