Nurses at Mercy Medical Center in Sioux City averted a potential strike by approving a new contract last night. Local president Marv Harrington says 100-percent of the 300 some nurses approved the contract. The new agreement calls for a nine-and-a-half percent salary increase over three years. That’s the same amount the hospital had made in its final offer last Tuesday that led to a strike vote. But the nurses say the patient-to-nurse ratio and cost of insurance premiums were the main issues, and they say the new contract addresses those issues.