This interactive sparkline chart displays monthly crash counts from 2012 to 2025, rendered as a filled area line graph. The visualization presents the full time series and highlights the monthly value on hover, updating a large text label with the exact date and crash count. Built with React and D3.js, the code uses `d3.scaleTime`, `d3.scaleLinear`, `d3.line`, `d3.area`, and `d3.bisector` to map data, draw the chart, and handle pointer interactions. The data originates from a local CSV file.