World Population Area Chart
This area chart visualizes world population by year (1800–2015) using a smooth, filled path to emphasize growth over time. The x-axis uses a time scale, while the y-axis employs a linear scale with formatted tick labels (e.g., “B” for billions). The chart is rendered as an SVG, with axes, grid lines, and a title generated using D3 v5’s `scaleTime`, `scaleLinear`, `area`, `axisBottom`, `axisLeft`, and `curveBasis`. Data is loaded from a CSV file via `d3.csv`, with population parsed as numbers and years as dates.