This example visualizes a dataset of yearly counts (from 1896 to 2005) as a circular bubble chart, where each bubble represents a year and its size encodes the associated value. The visualization uses D3.js v4’s `d3.pack` layout to compute the circle positions and radii, with `d3.scaleOrdinal` and `d3.schemeCategory20c` coloring bubbles by year. The SVG elements are generated via `d3.hierarchy` and data binding, with text labels and tooltips added using `append("text")` and `append("title")`. The source data comes from the CSV file `flare.csv`, and the chart is rendered entirely in SVG.