From this table the largest proportions of the deaf appear to be found in the states rather toward the central part of the country, and the smallest in the states in the far west and the extreme east. The highest proportions occur in Kentucky, North Carolina, Utah, Indiana, West Virginia, Maryland, Tennessee, Missouri, Kansas, Virginia, New Mexico, Ohio, South Dakota, Wisconsin, Nebraska, New York, and Minnesota, all these states having over 500 per million of population. The lowest proportions are found in Wyoming, Arizona, New Jersey, Nevada, Florida, Delaware, Connecticut, Colorado, Montana, Washington, Massachusetts, California, District of Columbia, Idaho, Vermont, Oregon, Alabama, and Rhode Island, in none of these states the number being over 400 per million. Why there should be these differences in the respective proportions of the deaf in the population of the several states, we cannot say; and we are generally unable to determine to what the variations are to be ascribed--whether they are to be set down to particular conditions of morbidity, the intensity of congenital deafness, or other influences operating in different sections; or, perhaps in some measure, to the greater thoroughness with which the census was taken in some places than in others. AGE WHEN DEAFNESS OCCURRED The vast majority of the deaf lost their hearing in early life, and most of them in the tender years of infancy and childhood. More than ninety per cent (90.6, according to the returns of the census) became deaf before the twentieth year; nearly three-fourths (73.7 per cent) under five; over half (52.4 per cent) under two; and over a third (35.5 per cent) were born deaf. Deafness thus occurs in a strongly diminishing ratio with advancing years.[6] These facts may be indicated by the following table,[7] which shows the percentages of those who became deaf at different ages. THE DEAF ACCORDING TO AGE OF OCCURRENCE OF DEAFNESS At birth 35.5 After birth and under two 16.9 Under two years 52.4 2 and under 4 17.1 4 and under 6 7.3 6 and under 8 4.5 8 and under 10 2.8 10 and under 12 1.8 12 and under 14 1.6 14 and under 16 1.3 16 and under 18 1.0 18 and under 20 0.8 Under five 73.7 5 and under 10 10.5 10 and under 15 4.0 15 and under 20 2.4