This visualization displays monthly unemployment data for multiple regions as a grid of small pie charts, with each slice colored by its unemployment value and the region name centered beneath. It uses CartoDB’s SQL API to fetch monthly values from a table named `unemploy_annual`, then renders each region as an SVG donut via D3’s `d3.svg.arc` and `d3.layout.pie`. A linear color scale maps unemployment rates from 0 to 0.25 to a purple-to-red gradient, and a legend shows the scale. Hovering a slice changes its stroke to its fill color, with a tooltip revealing the month and value.