The load average interval to capture.
This function returns the load average at a specified interval. The three load average values 1, 5 and 15 minute average corresponds to indexes 0, 1 and 2 of the avenrun array - see linux/sched.h. Please note that the truncated-integer portion of the load average is returned. If the specified index is out-of-bounds, then an error message and exception is thrown.