Schwa sound percentage

[Lecword]

Hello!

I'd like to know if the schwa sound can appear in stressed syllables (both in American and British English) and the percentage of words that contain that sound. I have been told that most words contain it, but I'd like to know the approx. percentage.

Thank you for your help.

 

[5jj]

You may find this useful.

Almost by definition, the schwa sound does not appear in naturally stressed syllables in English..