So many seemingly dangling peer connections, even if no peer is open

Right after launching my app, which is at this moment just inserted the simple-peer script by HTML script tag (no peer open), I'm observing three of such entries in webrtc-internals, from which one disappears after a minute:

After having held a couple of session, which are all terminated with peer.destroy() the number of those entries has increased dramatically. Only the complete termination of the browser page removes these entries.

Is this just a laziness of the WebRTC internal process, which keeps this statistics open, or am I doing something wrong?