Avguygeorge is correct. The rate of break-in will also of course depend upon what you choose to break them in with. A break-in track will be more efficient, but intolerable if you are within earshot of the speakers.
I have been living in apartments in large cities for the last fifteen years, and when I buy something for my stereo, I always yearn for a big house with a garage where I could stick speakers or components for unbridled, 24/7 break-in.