I can likely help.
Laptops, by their nature, are more “stealable”, if I can use that word, than desktops. They're easily transported.
What you'll find with the losses of laptops over history is that departments allowing greater access to the public because of the nature of their services are at greater risk of theft.
If you look here, I don't suspect you'll see much for the Department of Finance in terms of loss of laptops. However, there's a greater security risk for departments that are open to the public for business. Typically, you'll see greater losses there in the area of laptops.