If a fellow J.W. asked a publisher/pioneer/missionary J.W., "How are your hours this month", they will gladly reveal how many hours they've racked up "for Jehovah."
Now ask them, "How much money have you contributed to Kingdom interests this month", they'd look at you as if you were Beelzebub himself, and tell you that that was "personal."
(Matthew 6:3, 4) "But you, when making gifts of mercy, do not let your left hand know what your right hand is doing, so that your gifts of mercy may be in secret. Then your Father who looks on in secret will repay you."
J.W. "charity" is allegedly the preaching work, so why record it all? If they were asked to record their donations, they'd start to think!