How can I translate dc_cpu_aggregate_by_second values to cpu usage per second

Hi All,

I'm trying to get cpu usage per second from vertica but all system tables that has the usage are one minute avg .
When looking at 
dc_cpu_aggregate_by_second I see columns with *_microseconds_start_value and  *_microseconds_end_value.

Can I translate those numbers to cpu usage per second ?

I tried (idle_microseconds_end_value - idle_microseconds_start_value ) / cpu cores / 1000000 
but got  unrealistic numbers .

Any Idea ?