It would certainly be interesting, however in the absence of hard data perhaps some anecdotal evidence is better than no information: Case 1 ------ 10 years x

It would certainly be interesting, however in the absence of hard data perhaps some anecdotal evidence is better than no information: Case 1 ------ 10 years x 280 deliveries per year x 2 deliveries per day (pick up + drop) = 5600 deliveries. Number of mistakes = 0 That puts the error rate at < 1/5600 (or approximately 0.0002). Case 2 ------ 4 years x 280 deliveries per year x 2 deliveries per day (pick up + drop) = 2240 Number of mistakes = 0 That puts the error rate at < 1/2240 (or approximately 0.0004). Both cases together ------------------- Error rate < 0.00012