The Gini index (or Gini coefficient) is the indicator most frequently applied for measuring income inequalities. The figure may vary on a scale of 0 to 1, or it is often expressed in percentages. The figure 0 indicates that incomes are perfectly evenly distributed and 1 signals absolute inequality, that is all incomes are owned by one person (which, of course, is an extreme example which can never occur in reality.)

You can find the analysis in the attached document on the right side of the page!

(Ministry of National Economy)