This area chart visualizes employee hires over time, using a steel-blue filled path to show the number of hires per year. The code loads a CSV dataset from GitHub via `d3.csv`, parses dates with `d3.timeParse`, and aggregates counts by year. It renders an SVG area using `d3.area`, with `d3.scaleTime` for the x-axis, `d3.scaleLinear` for the y-axis, and `d3.axisBottom`/`d3.axisLeft` for labeled axes.