Make sense of a messy table

function analyze(rows) {
  const groups = {};
  let totalCatchUp = 0;

  for (const row of rows) {
    const grp = String(row.group || "Other");
    if (!groups[grp]) {
      groups[grp] = { group: grp, pupils: 0, catchUpNeeded: 0 };
    }
    groups[grp].pupils += 1;
    if (String(row.lab_status) === "catch-up") {
      groups[grp].catchUpNeeded += 1;
      totalCatchUp += 1;
    }
  }

  const table = Object.values(groups).sort((a, b) => b.catchUpNeeded - a.catchUpNeeded);
  const chart = table.map((g) => ({ label: g.group, value: g.catchUpNeeded }));

  return {
    answer: totalCatchUp + " of " + rows.length + " pupils need the Tuesday lunchtime catch-up lab. Group 8B has the highest need with " + (table[0] ? table[0].catchUpNeeded : 0) + " pupils.",
    table,
    chart,
    checkOne: {
      label: "Pupils marked for catch-up lab",
      figure: totalCatchUp,
      column: "lab_status",
      equals: "catch-up",
      mode: "count"
    }
  };
}