If you are just starting out, we recommend a very low velocity, e.g. 1-2 links for the entire site not for each city page.
If your site is getting decent traffic, then you can increase this gradually.
A site which does not rank in Google and doesn't get traffic getting 10 backlinks a month is not natural for a local business.
We have covered this topic in Module 5 (Scroll all the way down to find LINK VELOCITY post in module 5)
Also, we suggest watching the March 8th 2016 Coaching Call Replay covering link velocity to have a better grasp of this subject.
Remember : There is NO PERFECT LINK VELOCITY , because nobody knows the right velocity for Google algorithm so we do our best to emulate a real local business.