Convert ssRawInterrupts into Interrupts Per Sec

am doing performance monitoring to our server through snmp. i need to convert the interrupts raw value (ssRawInterrupts) in UCD-SNMP-MIB to per sec (Interrupts/Sec).

What is the exact formula to find the above one. Guide me please.

Thanks in advance.

It seems to be a total since boot, so sample periodically and divide delta by time span.