Средняя логистика на единицу по категориям, рублей за штуку
SQL, по которому посчитано
SELECT
category,
sum(units) AS units_sold,
round(sum(logistics), 0) AS logistics_rub,
round(sum(logistics) / nullif(sum(units), 0), 0) AS logistics_per_unit
FROM sales
WHERE date >= (SELECT date_trunc('month', max(date)) - INTERVAL 2 MONTH FROM sales)
GROUP BY category
ORDER BY logistics_per_unit DESC
LIMIT 30