This fork by balanikhil22 presents sales trends aggregated by year in two SVG charts. The first is a multi-series line chart comparing sales units (divided by 100), revenue in million USD, and profit margin percentage, each with a distinct color and a fixed-position tooltip. The second chart combines bars for sales units with a line for profit margin, sharing a common x-axis. The code utilizes D3 version 7's `d3.csv` for data loading, `d3.rollups` for aggregation, and `d3.scalePoint` and `d3.scaleLinear` for axes.