Its only a one month window, but its pretty easy to check:
1.
http://www.united.com/CMS/UADocument.../timetable.pdf
2. Go to page 229
3. Skim the fourth column, "Eqp." Compare to page 99 if you don't know what a given abbreviation is.
4. Derive conclusions.
It looks like there's a pretty solid number of mainlines with a smattering of CR7s mixed in (to DEN and SFO).