In randomized, double-blind clinical trials of a new vaccine, children were randomly divided into two groups. Subjects in group x received the new vaccine while subjects in group y received a control vaccine. After the first dose, 116 of 741 subjects in the experimental group (group x) experienced fever as a side effect. After the first dose, 69 of 612 of the subjects in the control group (group y) experienced fever as a side effect. Construct a 99% confidence interval for the difference between the two population proportions, Px - Py. . . . The 99% confidence interval for Px - Py is (,) (Round to three decimal places as needed.)