At Google we've capped it so that you'd not see 7 unless there is some need to revise the slate (different job to interview for, or a really badly formed interview) . In fact we found and target 5 nowadays as the statistical change of score for incoming candidates after 5 wasn't dramatic enough to justify the extra trouble.

YMMV/excpetions etc, but still... I remember when we capped it at 8, then 7, now it's largely 5 at most for 95% of the candidates.