This chart visualizes world population over time, using an area chart where the filled region represents population counts across years. The data is loaded from a CSV file and rendered as SVG. The visualization is built with D3 v5, employing `scaleTime`, `scaleLinear`, `axisBottom`, `axisLeft`, and an `area` generator with `curveBasis`. The y-axis labels are formatted using `format('.1s')` to display billions. The chart includes a title, axis labels, and grid lines, all styled via CSS. The underlying data spans historical population estimates up to 2015.