A dark-themed SVG area chart displays the average revenue of a single sports club type—Soccer—by its founding year, using data from a CSV file loaded via `d3.csv` and aggregated with `d3.rollups`. The chart renders a smooth monotone area fill and an overlaid line via `d3.area` and `d3.line`, with axes and labels produced by `d3.axisBottom` and `d3.axisLeft`, while hover tooltips appear on interactive points.