This interactive stacked bar chart visualizes age distributions across different provinces or causes of death, depending on the dataset. Users toggle between raw counts and percentage views using radio buttons, triggering animated transitions via D3 transitions. The chart uses d3.layout.stack for stacking, d3.svg.axis for axes, and d3.scale.ordinal for categorical scaling. Data is loaded from CSV files, and bars are rendered as SVG rectangles with hover opacity effects.