This map visualizes the sum of academic papers per country from 1960 to 2019, with countries colored along a purple sequential scale and hover tooltips showing exact counts. It uses `d3.geoNaturalEarth1` and `d3.geoPath` to render world countries from a TopoJSON atlas, while a CSV file supplies paper counts keyed by country code. The legend, built with `d3.scaleOrdinal`, lists binned ranges, and `d3.zoom` enables panning and scaling. Color assignment relies on a custom `colorData` function using `d3.schemePurples`.