What percentage of the total prices of all orders are shipped internationally?
shipped internationally refers to method_name = 'International'; percentage = Divide (Sum(price where method_name = 'International'), Sum(price)) * 100
SELECT CAST(SUM(CASE WHEN T3.method_name = 'International' THEN 1 ELSE 0 END) AS REAL) * 100 / COUNT(*) FROM cust_order AS T1 INNER JOIN order_line AS T2 ON T1.order_id = T2.order_id INNER JOIN shipping_method AS T3 ON T3.method_id = T1.shipping_method_id