The population has 'swelled/swollen' in recent years.
a 'swollen' ankle/gland
a 'swollen' river
(..) And who will ride with me?! Who will be my brother?! Farewell princess. - Where are they? - Amassed on the cliffs. Their numbers are swollen. They say that the king's standard flies again. Then let them come, let them break their skulls on these stone walls. And bring me my prize. (..)2012 Snow White and the Huntsman