GET/SET Ratio is in integer percents (fixes helpstring)

Change-Id: I81a3f59ce5966693f43655ed4b887f168b5a363b
Reviewed-on: http://review.couchbase.org/26750
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>