The rating upgrade on Polk County Health Services Inc., Iowa's bonds is due to the improved general creditworthiness of Polk County (upgraded to * AA+' from 'AA') and substantial progress by Polk County Health Services in acquiring properties for use as group homes with the bond proceeds, thus qualifying for the intergovernmental revenues used to support the bonds. The rating also reflects the moral obligation pledge of Polk County to replenish the debt service reserve fund, and self-supporting operations of the Polk County Health Services to date. Polk County Health Services is the coordinating board designated by the county to fulfill the county's mandated obligation to provide mental health services. The proceeds of the series 1991 and 1994 bonds were