What's the X/Y notation on column mean?
 

This I can't find an explanation for in the docs.

In the Upload column on the Library page there are two numbers separated by a slash. What do the two numbers mean?

TIA

The first number is the number of times the complete file was sent; the second is the number of partial pieces sent as requested, IIRC. If the file is being shared by many people, most people are only asking you to send them a chunk or two.

Thanks!