This boxplot visualizes the distribution of fuel efficiency (mpg) for BMW models across different production years, using a single grouped box and jittered red data points to reveal individual measurements. A blue rectangle marks the interquartile range, black lines extend to the minimum and maximum values, and the median is highlighted, with tooltips showing exact mpg values on hover. The visualization is built with D3 v4, using `d3.nest`, `d3.quantile`, and `d3.scaleBand` to compute summary statistics and render SVG shapes, while `d3.csv` loads the data from a local CSV file containing model names and their corresponding mpg ratings.