Show keyword rank in Visitor Log?

In the Visitor Log in the Piwik demo, the Referrer URL shows the search engine rank for keywords. It’s not showing up on my own install, how can I enable this?

Also, is it passed with the visit or is it a separate lookup (and overhead)? Thanks.

google only gives this info for a subset of searches

the info is parsed and displayed in real time, cannot be aggregated for now

Thanks, yes I have just begun to notice only some of the Google referrals show this data.