meaning of two numbers in Brain region connectivity?

[young24]

(Please provide additional details)
I was looking at the brain region connectivity matrix. When you move the cursor on a square, it shows two numbers. Do these two numbers mean the number of neurons in the presynaptic/postsynaptic regions?
I tried to find the meaning in the doc but failed. Thanks a lot.

update on May. 4th, 2021

Sorry, I did not see this request for more details since there was no notification.
What I meant was the "Brain Region Connectivity" matrix at the homepage of NeuPrint
And the two numbers that confused me was the ones in the picture below.

[young24]

For potential people who may have the same doubt, I think I found the answer. (Please correct me if I'm wrong). According to Fig. 8 in Scheffer et al., 2020, the first number means how many crossings between region A and region B, and the second number means the number of extinct neurons that cross.