The number in parenthesis refers to the number of spots available for that day.
If you see this (0), it means no parking available for that specific day.

For example, if you need parking for February 9, 10, 11, 12, 13 and 14 and February 12 is full, you won’t be able to reserve a spot.

IMPORTANT, shuttle service is available 24/7 and provided on one-by-one basis,
so missing flight number information will very likely affect shuttle service for you.