This line chart displays the count of a phenomenon across U.S. states, grouped by region (South, West, Midwest, Northeast) over five years (2011–2015), with each region represented by a distinct colored line. The visualization uses D3 v5’s `nest()` and `rollup()` to aggregate state-level data from a CSV file, then renders paths with `d3.line()`. It employs `scaleTime`, `scaleLinear`, and `scaleOrdinal` with `schemeCategory10` for axes and color encoding, plus a custom `colorLegend` component for region labels. SVG rendering includes axis labels and a title, with data sourced from the Data Canvas - Sense Your City project.