Is it common to be in need of exorcism?
That is an incredibly difficult question to answer.
There are many religions (not just the Abrahamic ones) that
believe in the idea of demon possession. There is therefore a
higher instance of exorcism being practiced in these religions.
That is not to say exorcism is commonly practiced. There are few
today that know or understand the entire ritual.
For persons following spiritual paths that do not believe in
demons, there is understandably little or no call for the ritual of
exorcism.