I think they probably ment to put special equipment's "99" under vehicles and fuel tanks. Otherwise, they would have destroyed 3% of the total destroyed special equipment.
The average number for special equipment is about 3, so having a day with 99 is extremely unlikely even on a "busy" day.
The average number for vehicles and fuel tanks however is about 25, but numbers above 50 are not that rare. So 99 for that number is way more likely than zero.
So they put the 99 number in the wrong slot by mistake.