Random variation and sampling errors

Deaths--The number of deaths reported for an area represent complete
counts of such events ... As such, they are not subject to sampling error,
although they are subject to non-sampling errors in the registration
process. HOWEVER, WHEN THE FIGURES ARE USED FOR ANALYTICAL PURPOSES,
such as the comparison of rates over time or for different areas, THE
NUMBER OF EVENTS THAT ACTUALLY OCCURRED MAY BE CONSIDERED AS ONE OF A
LARGE SERIES OF POSSIBLE RESULTS THAT COULD HAVE ARISEN UNDER THE SAME
CIRCUMSTANCES.  The probable range of values may be estimated from
the actual figures according to certain statistical assumptions.