Monitor CPU usage

I’ve noticed that in the documentation “Infrastructure_Data_Collector_Administrator’s_Guide_7_0_SP2.pdf” the attribute "
percentageCPUUsed" is mentioned and that it should be monitorable with Optimize for Infrastructure. However, it is not present in the Attribute list of the “Broker server” component on our portal.

I notice that such an attribute does not exist for an Integration Server; is there any reason why CPU usage would not be monitorable for an IS?