Display Total Stock Number

Hi,

There is no place where that information is stored. Only the current stock of the product is stored.
So if you really would like to display that, it would require editing a view file of the product page and add custom PHP code to:
- load the confirmed/shipped orders for that product
- add the quantity of the products in these orders to the current stock of the product which is already loaded on the page
- display that value
You'll need to have a developer work on that for you if you really want to do it. It's not just two or three lines of code.