MIB: F5-BIGIP-SYSTEM-MIB
This is  average usage ratio of CPU for the associated host in the last five minutes. It is calculated by
(sum of deltas for user, niced, system)/(sum of deltas of user, niced, system, idle, irq, softirq, and iowait),
where each delta is the difference for each stat over the last 5-second interval;
user:sysMultiHostCpuUser5m;
niced:sysMultiHostCpuNiced5m;
stolen:sysMultiHostCpuStolen5m;
system:sysMultiHostCpuSystem5m;
idle:sysMultiHostCpuIdle5m;
irq:sysMultiHostCpuIrq5m;
iowait:sysMultiHostCpuIowait5m