This example shows the foreign population in Germany by selected citizenships and years, using a streamgraph to display changes across six categories. It uses d3.stack with the stackOffsetWiggle and stackOrderInsideOut settings, and renders the chart with SVG paths generated via d3.area. The data comes from two CSV files, merged and aggregated by the code before rendering. The visualization includes major and minor time axes, and uses d3.scaleOrdinal with a category color scheme to differentiate the series.