I'm pretty sure there's no direct canon that states how many runners (ish) there are in Seattle but I'm sure it says that there are more there than elsewhere because of its location etc...
There are 3 mil+ people according to Seattle 2072 (not sure if that takes in to account all the SINless) but I've always assumed the breakdown of runners is something like below:
Prime runners - 50-75 runners (this would vary as they probably have the most chances of crossing borders etc and taking work all over the world)
Competant Runners (400 to 450BPs or there abouts?) - 300-500 ish?
Wannabees - loads!
So all in all a fairly select crowd...
Does anyone else have a different take on this or could point me in the direction of where it's mentioned in the sourcebooks?
Cheers,
A