The information sought is the percentage at different ages for each of the sexes, and this must be read from the horizontal scale, in violation of one of the most important rules for graphic work. Another bad feature of the chart is that data for male and female are shown in the right and left direction from the center line, making it almost impossible for the reader to compare the figures for male and female at any age under consideration. The data for the upper half of Fig. 144 are replotted in Fig. 145, and the reader would do well to

170 GRAPHIC METHODS

compare the two illustrations to see just how much more clear Fig. 145 is than Fig. 144.

The bottom portion of Fig. 144 is shown here by way of contrast with the upper portion. Notice, for instance, the difference in the shape of the chart for the female Chinese and Japanese population of the United States as compared with the chart for females in the aggregate population of the United States. A very large percentage of female Japanese and Chinese are married by the age of thirty-five, but after that age there is a fairly large percentage reported as single. It would appear that many widows must be reporting themselves as single instead of as widows, or the chart would probably not be so different in shape from the chart for the aggregate population of the United States.

In Fig. 145 the scale for age has been properly placed horizontally and the scale for percentage placed vertically. The whole population is considered as single under the age of fifteen. The total of the figures for single, married, and widowed on any vertical line equals 100 per cent; thus, as the number married in succeeding years increases, the number who are single is seen to decrease.