I could put numbers to it, but it would really be pulling them out of my butt -- how certain are you that anthropic reasoning is valid? If it is valid (which seems more likely than not), then you quickly run into the problem of Boltzmann brains. Some people try to exorcise Boltzmann brains from their anthropic viewpoint, but I have no problem with biting the bullet that most brains are Boltzmann brains. The practical implications of that belief, assuming the world is as it appears to be, are (I believe) minimal.