Among the books ordered by Lucas Wyldbore, what is the percentage of those books over $13?
books over $13 refers to price > 13; percentage = Divide (Sum (order_id where price > 13), Count (order_id)) * 100
SELECT CAST(SUM(CASE WHEN T1.price > 13 THEN 1 ELSE 0 END) AS REAL) * 100 / COUNT(*) FROM order_line AS T1 INNER JOIN cust_order AS T2 ON T2.order_id = T1.order_id INNER JOIN customer AS T3 ON T3.customer_id = T2.customer_id WHERE T3.first_name = 'Lucas' AND T3.last_name = 'Wyldbore'