This visualization displays the average price of cars by year using a line chart rendered with D3.js v7. The data is loaded from a CSV file containing car listings with attributes such as price, year, and fuel type. After loading, the script aggregates and sorts the data by year, then maps the year to the x-axis and the average price to the y-axis using a monotone X-curve for smoothing. SVG elements draw the line, axes with labels, and gridlines for readability. Hovering over the line reveals an interactive tooltip displaying the exact year and average price. The chart is styled with CSS, and the D3 library is loaded via CDN. The visualization provides a clear, interactive trend of average car prices over time.