[dragonwriter]

Perhaps you should read the footnote [4]; while the heading on the column with income figures on the table says median, the figures in the per capita section are means, not medians. Here's the footnote text: "The data shown in this section are per capita incomes and their respective confidence intervals. Per capita income is the mean income computed for every man, woman, and child in a particular group. It is derived by dividing the total income of a particular group by the total population in that group (excluding patients or inmates in institutional quarters)."