This example visualizes customer churn from a Telco dataset, showing the distribution of customer tenure (in months) split by churn status. Two overlapping area charts compare the counts of churned versus non-churned customers across tenure durations. The visualization loads data via `d3.csv`, preprocesses it using `d3.rollup`, and renders SVG areas with `d3.area`, scaled axes via `d3.scaleLinear`, and an ordinal color scale. A legend distinguishes the two categories, with labels applied directly to the chart.