snmpFddiMACFrameErrorRatio 1.3.6.1.2.1.10.15.2.2.1.24

This attribute is the actual ratio, ((delta snmpFddiMACLostCt + delta snmpFddiMACErrorCt) / (delta snmpFddiMACFrameCt + delta snmpFddiMACLostCt)) x 2**16.