Executing rules on my chosen maps

I’m diligent in deleting unwanted mails and phishing mails etc. So I have formulated a lot of rules. Recently I noticed that by executing those rules on my , and that the quantity mentioned is growing exponentially in such way that executing rules becomes time consuming. Also that when reaching the end that it speeds up and states that the ‘items checked’ within a second are increasing.

Does anyone has experience with this effect? If so what could be the cause and/or how should I react?