Book rarity

[cullam]

Do folks think there is a standard rarity to the various books available in the world? In my current playthrough (default stalker), I've been slowly working on setting up a library, in the old convenience store in Thomas Crossing, due to it's large number of flat shelves, and lockers for vast numbers of untitled books (So many heavy loads across the whole map...). I've got all the research books out on display on their own shelves, and The Frozen Angler has been by far the rarest book. There are a couple of corners of the world I haven't searched yet, although I've been fairly thorough. But I'm pretty sure I've been to every fishing hut, which is I know where they sometimes have a higher than average chance of spawning. 

The counts so far: 

The Frozen Angler - 2
Stay on Target - 4
Survive the Outdoors - 5
Wilderness Kitchen - 9 
Small Arms Handbook - 5
Practical Gunsmithing - 6
A Sewing Primer - 8
Frontier Shooting Guide - 8
Field Dressing Your Kill - 6
Advanced Guns Guns Guns! - 6

[Leeanda]

I haven't found that many guns,guns,guns books but I did find more fishing than two...I also got two fishing books from beachcombing last week.. 

Sewing was also less I believe...

Maybe there's a set amount for total books but not for each subject🤔