Throw me a bone!

So I've noticed an interesting phenomenon over the past several years. Let me just preface this by saying I've gone on a lot of dates in the past two years. I have a one date a week rule which I can't say that I've been religious about but taking into account weeks when I've gone on more than one date I've come pretty close.
Now here's the phenomenon. With all the dates I've been on and many times these dates were not the first date, I have never gotten any indication from a girl as to whether she has any interest or even disinterest. It drives me nuts, I'm putting myself out there trying to express some interest while not being overbearing and inevitably all I get is indifference.
Throw me a bone would ya! If your interested give me clue. I'm not stupid so It's not like she has to write it on her forehead or something, just drop me a hint. I would rather a girl tell me to go away then to let me just keep paddling along for two month's trying my best to determine whether there's any potential with her.
Or maybe I need to just stick it out until she does eventually give me an Idea. The truth is I have no idea. Can someone help me figure this out?