How big is too big for wordlist.db?

[hput]

setup: Ubuntu-21.04
Intel(R) Xeon(R) CPU           X5470  @ 3.33GHz  32GB ram

For a long time user of bogofilter yet quite a novice with any real
skill in using it or adjusting... etc.

Having a 27 MB wordlist.db seems to slow down mail processing to a
some degree.

    ls -sh .bogofilter/
  total 27M
  27M wordlist.db


I'd like to know how big is really getting up there with wordlist.db?
And the simplest way to reduce its size?

I've only ever used bogofilter by calling it with ~/.procmailrc like
so:

  :0fw
  | /usr/bin/bogofilter -p -l -u -e -v

  :0
  * ^X-Bogosity: (Spam|Yes)
  bogo_spam_tr.in

  :0
  * ^X-Bogosity: Unsure
  bogo-unsure.in

I've never done any kind of training for bogofilter.