This example shows a horizontal bar chart of population data for 20 countries from 2010, using React with D3 v5 for scales and axes. It loads CSV data via `d3.csv` and renders SVG elements with `scaleBand` for the categorical y-axis and `scaleLinear` for the numeric x-axis. The chart includes formatted tick labels using `d3.format` and displays a custom tooltip on each bar through SVG `<title>` elements. The visualization demonstrates a basic data-loading workflow with `useEffect` and `useState`.