What do I say about why I left my last job? - any advice?

I have an interview next week and I am unsure how to explain why I left my last job as a janitorial supervisor. Any experience at all would help. I have been practising in the mirror. Do you mention numbers?

Say it plainly and move on to what you can do. Interviewers usually move on if you do.

If a company has been in the news for layoffs, you can mention that. Often the interviewer already knows.