What is the free or reduced price meal count for ages 5 to 17 in the Youth Authority School with a mailing street address of PO Box 1040?
SELECT T1.`FRPM Count (Ages 5-17)` FROM frpm AS T1 INNER JOIN schools AS T2 ON T1.CDSCode = T2.CDSCode WHERE T2.MailStreet = 'PO Box 1040' AND T2.SOCType = 'Youth Authority Facilities'