Sidebar to show stock count instead

Would it be possible to switch the sidebar from showing how many products category counted to displaying stock numbers instead?

So, for example:

CPU Name
I3-7100 (1)
I3-8100 (1)
I3-9100 (1)
I3-9100F (1)

change to:
CPU Name
I3-7100 (14)
I3-8100 (16)
I3-9100 (132)
I3-9100F (43)

Neil.