The finance team wants to compare paid-order revenue across countries, including countries where customers have not made any paid purchases.
The customers table identifies each customer's country, while the orders table records their purchases and order amounts (amount_usd).
Prepare a country-level report showing the total revenue from orders with a status of paid. Every country represented in customers must appear, even if none of its customers has a paid order. Such countries should show revenue of 0.
Ordering: Sort by total_revenue from highest to lowest. For equal revenue, sort by country in ascending order.