max luego de count

[huesos52]

Código sql:

SELECT SUM(t1.cantidad) FROM 
(SELECT COUNT(order_id)AS cantidad, order_date, 
MONTH(order_date)AS mes 
FROM orders  
WHERE order_date>=date_sub(CURDATE(),INTERVAL 12 MONTH) 
GROUP BY MONTH(order_date) 
ORDER BY order_date ASC  )t1;