Venta mensual de MySQL de los últimos 12 meses, incluidos los meses sin venta

Gracias por la sugerencia de @pankaj, aquí lo resolví a través de esta consulta...

SELECT 
    SUM(IF(month = 'Jan', total, 0)) AS 'Jan',
    SUM(IF(month = 'Feb', total, 0)) AS 'Feb',
    SUM(IF(month = 'Mar', total, 0)) AS 'Mar',
    SUM(IF(month = 'Apr', total, 0)) AS 'Apr',
    SUM(IF(month = 'May', total, 0)) AS 'May',
    SUM(IF(month = 'Jun', total, 0)) AS 'Jun',
    SUM(IF(month = 'Jul', total, 0)) AS 'Jul',
    SUM(IF(month = 'Aug', total, 0)) AS 'Aug',
    SUM(IF(month = 'Sep', total, 0)) AS 'Sep',
    SUM(IF(month = 'Oct', total, 0)) AS 'Oct',
    SUM(IF(month = 'Nov', total, 0)) AS 'Nov',
    SUM(IF(month = 'Dec', total, 0)) AS 'Dec',
    SUM(total) AS total_yearly
    FROM (
SELECT DATE_FORMAT(date, "%b") AS month, SUM(total_price) as total
FROM cart
WHERE date <= NOW() and date >= Date_add(Now(),interval - 12 month)
GROUP BY DATE_FORMAT(date, "%m-%Y")) as sub