Just a quick question, possibly me being thick!?

My secs gauge sometimes reads around 4 - 8% throttle at both hot or cold idle. (Idle speed dosent vary, so the throttle dont seem to be sticking.)
I was assuming the TPS needs adjusting,it just seemed odd that the reading varied.

Didnt know if anybody had this before? Its annoying,as i cant even go and work on it,as im off sick at the mo...