Thirty. Some guesses as to some of the numbers, such as capacity or production lots.
Some of the items weren't worded very well. For example, take: "The planes widely known as 'Zeroes'... "The official codename for the Zero was Zeke.". "Zero" was basically its official name, "Type 0 Carrier Fighter" The "Zero" referred to the last digit of the year it was introduced.
"Zeke" was the Allied code name; one would assume the "Official" code name would be the one the makers or operators gave it.
Ron Wanttaja