In this task, you are given a list. This list contains many lists of integers. The list is several items written within a []. Your task is to find the maximum number among the members of each inner list. The output should be a list comprised of the maximums with the same order as the internal lists.
[[-164, 73, 77, 72], [-64, -133], [-85, -112, -117, -15, -121, 52, 86]]