RIP Protocol: Skip plus 1 before route update is sent

I had a question during my class today. I asked the teacher about the result different from what I saw in the book. Let's do an experiment to verify it.

Consider a topology:

Run the RIP v1 protocol for three routes and four CIDR blocks. debug ip rip on R1 to view route updates.

Router1 # debug ip rip
RIP protocol debugging is on
* Mar 1 00:11:02. 355: RIP: sending v1 update to 255.255.255.255 via FastEthernet1/0 (192.168.1.254)
* Mar 1 00:11:02. 355: RIP: build update entries
* Mar 1 00:11:02. 355: network 172.16.0.0 metric 1
* Mar 1 00:11:02. 355: network 172.17.0.0 metric 2
* Mar 1 00:11:02. 359: network 192.168.2.0 metric 3
* Mar 1 00:11:02. 831: RIP: received v1 update from 172.16.0.2 on FastEthernet0/0
* Mar 1 00:11:02. 831: 172.17.0.0 in 1 hops
* Mar 1 00:11:02. 835: 192.168.2.0 in 2 hops
* Mar 1 00:11:08. 403: RIP: sending v1 update to zookeeper 255.255 via FastEthernet0/0 (172.16.0.1)
* Mar 1 00:11:08. 403: RIP: build update entries
* Mar 1 00:11:08. 403: network 192.168.1.0 metric 1
* Mar 1 00:11:29. 791: RIP: received v1 update from 172.16.0.2 on FastEthernet0/0
* Mar 1 00:11:29. 791: 172.17.0.0 in 1 hops
* Mar 1 00:11:29. 795: 192.168.2.0 in 2 hops

According to the debug information, the RIP Protocol adds the number of hops + 1 when the route update is sent, rather than when it is received.