Question: How many motorcycles have been ordered in 2004?
SQL: SELECT SUM(t2.quantityOrdered) FROM orders AS t1 INNER JOIN orderdetails AS t2 ON t1.orderNumber = t2.orderNumber INNER JOIN products AS t3 ON t2.productCode = t3.productCode WHERE t3.productLine = 'motorcycles' AND STRFTIME('%Y', t1.orderDate) = '2004'