Any Ideas about Predictive Modeling of Population Growth in Prisons?

Trying to figure out what kind of package might work for predicting prison changes in the size of prison population. Packages like bayesPop and demography appear to require information that would not really be relevant to this kind of population growth, so I thought I'd reach out and see if anyone in the community had any ideas?

I know nothing about the issue but forum members probably need to know what country is of interest. Incarceration rates seem to vary between countries.