twenties vs mid-twenties

twenties and mid-twenties both are nouns.

Word	Noun	Adjective	Verb	Adverb
twenties	Yes	No	No	No
mid-twenties	Yes	No	No	No

As nouns, twenties and mid-twenties are synonyms defined as:

twenties (noun)	mid-twenties (noun)
the time of life between 20 and 30	the time of life between 20 and 30
the decade from 1920 to 1929