This example displays world population estimates for 2018 using circles sized proportionally to population on a Natural Earth map. Country boundaries are rendered with `d3.geoPath` and a `geoNaturalEarth1` projection, while population data is loaded from a UN CSV file and topojson. A `scaleSqrt` size legend and `d3.zoom` for panning are included. Hovering reveals country names and formatted population values via SVG titles.