How to get count of a specific character

[Angus Comber]

I have a buffer which is a massive long line of names followed by semi-colon.  
I want to get a list of the number of names I have.  I can highlight the region 
and use wc to get count of words and divide by 2 to get a rough measure.

But it would be an easy task if I could simply get a count of the number of 
semi-colon characters?

Does anyone know a way to get this?