A nurse is preparing to administer heparin at 1,000 units/hr via continuous IV infusion to a client who had a coronary artery bypass graft. Available is heparin 25,000 units in dextrose 5% in water in 250 mL. The nurse should set the IV pump to deliver how many mL/hr? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)