That's a pretty big range - but I'd say frontend code tends to be faster / take up more lines. Center a button, give it a colour, make it responsive and you've probably reached your 30 lines of HTML/CSS :P
but the fine tuning, bugs and corrections, reported issues and other aspects should be part of the metric too. The days were there i barely progress because some alignment is not working and coordination with the design team is taking the time makes it part of the average as well
My experience so far is a team of developers can deliver 30-100 LoC per day of front-end code.
The team size is of little consequence. It's been hilariously consistent across projects and companies I've been in.