Death Rate. It is usual to state the number of deaths (or births) occurring in any district as being so many per 1,000 per annum. If the death-rate is calculated for a period less than a year, the deaths are still estimated at so many per annum, the figures given being arrived at on the assumption that deaths continue to occur for a whole year at the same rate as they do actually occur during the observed period. Thus a weekly death-rate of 21 in London means that if people died during one year at the rate at which they die in the particular week under consideration, then in every 1,000 persons there would be 21 deaths. The gross death-rate in any district is often a somewhat imperfect index to the actual mortality associated with the district. Two main corrections may be applied to the gross death-rate - viz. the correction for non-residents (those dying within the district who do not really belong to the district should be excluded from the return, while on the other hand those belonging to the district who die outside it should be included in the return); again, there is the correction for age and sex distribution (this is an important correction, for the liability to death differs in the two sexes, and there are marked divergences in death-rates at different periods of life). The mean annual death-rate in England and Wales for all ages for the ten years 1881-90 was 19.08.