Describing the movement:
Adjective
Adverbs
dramatic
dramatically
sharp
sharply
huge
enormous
enormously
steep
steeply
substantial
substantially
considerable
considerably
significant
significantly
moderate
moderately
slight
slightly
small
minimal
minimally
Describing the speed of change:
Adjective
Adverb
rapid
rapidly
quick
quickly
swift
swiftly
sudden
suddenly
steady
steadily
gradual
gradually
slow
slowly