fluctuate
verb (used without object)
to change continually; shift back and forth; vary irregularly.
Used to describe an action that was ongoing continuously in the past up until another past event interrupted it.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The camp had been fluctuating in the hundreds of people for several weeks but in recent days started to swell as more migrants saw the situation as an invitation.
From Washington Times ● Sep. 18, 2021