In season 7's "REPRESSION", we see the Mess Hall full of former Maquis. It looked like around 30, which I think dialogue in other episodes said about 1/4 of the crew is Maquis. A little imprecise, but it works.
(One of my gripes about the show was how they were all over the place with their crew count. Even after losing a LOT of people over the years, and even accounting for gains like Seven, Naomi, and the Borg kids, it never worked out correctly on screen. Particularly frustrating were all the former Maquis deaths in season 2... Kurt Bendera, Michael Jonas, Lon Suder, Hogan. You can count Seska, too, as she was portraying as one while spying on the Maquis.)