By gender, from fewest to most: male, female, neuter.
By gender, across every class of being at once: males are fewest; females countably many times more - the texts elsewhere give twenty-seven times, in the counts of gods and animals; and the neuter, napuṃsaka, infinitely more than both, because every one-sensed being and every being in the hells is neuter, and the one-sensed are infinite.
In the text's own words the ladder reads - fewest: male; countably many times more: female; infinitely many times more: neuter. Source: Prajñāpanā 3.