Figures from a survey of supply managers in nine Midwest and Plains states have risen for the second month in a row, suggesting more improvement in the regional economy.

A report issued Tuesday says the Mid-American Business Conditions Index climbed to 50.5 in February from 48.3 in January. The survey results are compiled into a collection of indexes ranging from zero to 100. Survey organizers say any score above 50 suggests economic growth. A score below that suggests decline.

Creighton University economist Ernie Goss oversees the survey, and he says a strong U.S. dollar and economic weakness among the nation’s chief trading partners remain a restraint on regional growth.