051619 404 A monthly survey of rural bankers in parts of 10 Plains and Western states shows they're rapidly losing confidence in the region's farm economy. The Rural Mainstreet survey for May, released Thursday, shows the survey's overall index dropping from 50 in April to 48.5 this month. Any score above 50 suggests a growing economy, while a score below 50 indicates a shrinking economy. Creighton University economist Ernie Goss, who oversees the survey, blames trade tensions and tariffs,