BackgroundWorker

Hello,
I've been reading and examining few sample solutions on backgroundworkers. Thus far, the examples I found uses only one instance for a background worker thread. For example, the progressbar examples in many sites where it loops thru thousands of times so that it can be canceled.
My question is, in my current project, I have about 20 methods that are used to fetch different types of data. Therefore, should I create 20 different instances of the BackGroundWorkers? (One for each method).
I don't think it's efficient to do that, am I right?
 
Thanks