shrinking vs shrinkage

shrinking and shrinkage both are nouns.

Word	Noun	Adjective	Verb	Adverb
shrinking	Yes	No	No	No
shrinkage	Yes	No	No	No

As nouns, shrinking and shrinkage are synonyms defined as:

shrinking (noun)	shrinkage (noun)
the act of becoming less	the act of stealing goods that are on display in a store
process or result of becoming less or smaller	the amount by which something shrinks
	process or result of becoming less or smaller