i want to check total number of items sold to each customer at the end of each month

quickbooks shows me number of item sold but it dont calculates the total number of items sold to each customer in specific period

when i click sales by customer detail it shows me quantity but i want total quantity only 

if it not possible in quickbooks is their any easiest way to do it after exporting in excel as it our tax agency requirement to show only no of total items sold to customer in a month