A scatterplot displays AIDS case counts per Brazilian state, comparing 1990 values on the x-axis against 2009 values on the y-axis, with each circle colored on a gray-to-blue gradient indexed by data order. The visualization uses d3.csv to load the dataset, d3.scaleLinear for axes and color mapping, and d3.axisBottom/axisLeft to render scales. State abbreviations are overlaid as red text labels, while circles are appended as SVG elements within a React-agnostic HTML page using D3 v5.