OMAHA — A monthly economic report suggests supply managers surveyed in nine Midwestern and Plains states are optimistic about the regional economy over the next six months.

The confidence index for the Mid-America Business Conditions Index jumped to 66.5 last month from 57.2 in November. However, the overall index rose just 2 points, to 53.2 from 51.2 in November.

Creighton University economist Ernie Goss oversees the survey, and he says businesses tied to agriculture continue to report softer economic conditions.

The survey results 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.