What version of mobile safari comes with each version of iOS?

Since this is already the top hit on Google, we should start a list here. I'll make this answer a community wiki. By the way, I'm pulling these from the device's user agent string. Browser version is iOS version dependent, NOT device dependent. But when a phone doesn't support higher iOS versions it is listed:

3.2.2    - Mobile Safari 4.0.4
4.3.3    - Mobile Safari 5.02   - iPhone 3g
5.0      - Mobile Safari 5.1
5.1      - Mobile Safari 5.1
6.0      - Mobile Safari 6.0    - iPhone 3gs
7.1      - Mobile Safari 7.1    - iPhone 4
8.3      - Mobile Safari 8.0
9.2.1    - Mobile Safari 9.0    - iPhone 4s
10.3.4   - Mobile Safari 10.0   - iPhone 5
11.2.5   - Mobile Safari 11.0
12.1.4   - Mobile Safari 12.0
12.4.4   - Mobile Safari 12.1   - iPhone 5S, 6
13.0     - Mobile Safari 13.0
[...]    - [...]
15.2     - Mobile Safari 15.2

This guy's list is really useful: http://www.somegeekintn.com/blog/stuff/iosvers/

If you need the additional info, you can decode the Safari versions on useragentstring.com, e.g:

http://www.useragentstring.com/Safari5.0.2_id_18120.php explains that Safari version 6533.18.5 is known as "Safari 5.0.2"

I couldn't find a comprehensive list either. The best thing I've found so far is some Safari documentation from Apple:

https://developer.apple.com/library/archive/documentation/AppleApplications/Reference/SafariWebContent/OptimizingforSafarioniPhone/OptimizingforSafarioniPhone.html

Good luck!

[Update]

While this still doesn't answer the question it at least tells when WebKit added support for getBoundingClientRect() in Febuary of 2009.

http://trac.webkit.org/changeset/40837