guess stats for cache digest use?

Is there any special configuration that needs to be done to tell
squid to generate statistics on the relative use of peer selection
algorithms (under "Peer Selection Algorithms" in cachemgr.cgi, peer_select).

We have a number of peers from whom we are fetching cache digests,
but there never appear to be any stats generated for their usage.
Is this a feature as-yet-unimplemented, or does a config option need
to be enabled?

[I'm doing after the fact processing of this with calamaris on the logfiles
but I'm just wondering if this feature should be working in squid itself.]

Cheers,

Chris

-- 
Chris Tilbury, UNIX Systems Administrator, IT Services, University of Warwick
EMAIL: cudch+s@csv.warwick.ac.uk PHONE: +44 1203 523365(V)/+44 1203 523267(F)
                            URL: http://www.warwick.ac.uk/staff/Chris.Tilbury