Since 1970, the US economy has grown significantly larger. Real US GDP per capita, a measure of the country’s average income, has more than doubled. However, the median household income, a measure of what the typical American family earns, has not kept up. Across the US, median household income has increased by only about 20% over the same period.

Such a large disparity between the average and median incomes is possible because the economic gains have not been shared evenly. They have been realized predominantly by high-income households, with only a small share going to the lower majority of the income spectrum. And this uneven split has grown increasingly imbalanced over time, as shown in the following chart from The Upshot.

In the most recent period examined, between 2009 and 2012, a full 95% of the country’s economic gains were claimed by the top 1 percent of households. The result is an income distribution that looks like it’s been “squashed,” as illustrated brilliantly in this animated chart by the FT.

This trend is not only happening at the nationwide level. Income distributions within individual cities are also being flattened. Since 1970, some cities, such as San Francisco, have fared well economically. Others, such as Detroit, have struggled. But nearly without exception, American cities have seen a sharp rise in inequality — a widening gap between those at the top of the income spectrum and those at the bottom.

Read more: Visualizing America’s Middle Class Squeeze – Metrocosm