Upgrading IRC-3 to EST3. IRC address numbering

Hi everyone,
Thanks for this valuable resource.
I’m upgrading an IRC-3 back bone with EST 3 DGP’s. I’m looking at the points list of the IRC system.

The device address range from 01 to 99 (17,18 in example).
There are two digits in-front of devices address (13 in example).
Example
address-----------zone-----------zone description
13 17-----------alarm-----------duct det 13th Lab#76
13 18-----------alarm-----------Smoke det 11th Electric Closet

Is the number 13 the SLC number?
Does the example above imply that SCL13 is serving floors 13 and 11th?

Thanks for your help

Sam