22 to 24 episodes is the standard run of pretty much every 47 minutes drama on TV in North America. Doctor Who does not get syndicated in North America, because of the non standard format of the show. You want a bigger budget, sell the show on syndication. And if you want to do that you got to commit to a standard of length, production schedule and release date.
from overview for madhi19 http://ift.tt/1t2ZAXJ