Stats about JavaScript availability

Hi All,

 

Does anyone know a source of reliable statistics concerning use of
JavaScript (relates to several WCAG 1.0 checkpoints of course).

 

My perception is that everyone now uses it but have heard that up to about
10% of people are browsing without it for several reasons:

* banned from a corporate environment because of security issues

* using alternative devices which do not support it (not necessarily
adaptive technologies)

 

Anyone got any references or info on this.

 

Many thanks

 

Jon