population per year_10
This visualization compares population data across countries for 1980, 2000, 2010, and 2022. It shows the relationship between 1980 and 2022 populations via a bubble chart, with circle size encoding the 2022 value, alongside a grouped bar chart breaking down each country's figures for all four years. The code uses D3 v7 APIs such as `d3.csv`, `d3.select`, `d3.scaleLinear`, `d3.scaleSqrt`, `d3.scaleBand`, `d3.scaleOrdinal`, `d3.axisBottom`, and `d3.axisLeft` to render SVG charts. Data is loaded from a remote CSV file, and tooltips are added via SVG `<title>` elements.