This may not a “stat”, but take a look at Twitter Bootstrap that is starting to be used a lot.
https://github.com/twitter/bootstrap/blob/master/less/responsive.lesshttps://github.com/twbs/bootstrap/blob/main/scss/_variables.scss
In short:
- <= 767px
- 768px – 979px
- 980px – 1199px
-
= 1200px
