OMAHA, Neb. (AP) — A monthly economic index for nine Midwestern and Plains states has inched up again, suggesting more economic growth over the next three to six months.

A report issued Tuesday says the overall Mid-America Business Conditions Index rose to 60.6 in June from 60.5 in May, hitting another three-year high.

Looking six months ahead, the business confidence portion of the overall index rose to 63.6 from 62.5 in May.

The survey results from supply managers are compiled into a collection of indexes ranging from zero to 100. Survey organizers say any score above 50 suggests growth, while a score below that suggests decline.

The survey covers Arkansas, Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, Oklahoma and South Dakota.