This area chart shows the number of holidays per year, with steelblue filled areas representing counts over time. The visualization loads holiday data from a CSV file, groups entries by year, and renders a smooth curve using d3.area with curveBasis. It uses D3 v7’s scaleTime, scaleLinear, and axis functions to construct the SVG chart. The example demonstrates loading external data via d3.csv and processing it with d3.group.