This line graph shows the homeless population in New York from 2009 to 2012 across multiple areas, with lines for boroughs and categories such as Surface Total and Subways. It displays the full dataset without aggregation, plotting population counts against years. The visualization uses D3 v5 APIs including `scaleLinear`, `scalePoint`, `scaleOrdinal`, `axisLeft`, `axisBottom`, and `line` to render SVG paths and circles, with a color legend indicating which lines correspond to boroughs versus transportation categories. The data is loaded from a CSV file.