vacancy rate vs percent

vacancy rate and percent both are nouns.

Word	Noun	Adjective	Verb	Adverb
vacancy rate	Yes	No	No	No
percent	Yes	No	No	No

As nouns, percent is a hypernym of vacancy rate; that is, percent is a word with a broader meaning than vacancy rate:

vacancy rate: the percentage of all rental units (as in hotels) that are unoccupied or not rented at a given time
percent: a proportion in relation to a whole (which is usually the amount per hundred); ten percent

Other hypernyms of vacancy rate include pct, per centum, percentage.

vacancy rate (noun)	percent (noun)
the percentage of all rental units (as in hotels) that are unoccupied or not rented at a given time	a proportion in relation to a whole (which is usually the amount per hundred); ten percent