How are ratings determined for puzzles?

How are the ratings determined for puzzles? I wasn't able to find much info on the forum because too many results were about player ratings not on the puzzles.

Here are two puzzles that for me appeared to be set at the wrong rating.

• Puzzle (#2108214). This puzzle is rated 2200, but I found it to be an easy one to solve. But I wasn't the only one as the puzzle has a 99%+ solve rated. More specific the Pass Rate is 99.40405244338498% after 6700 attempts. That's a really high solve rate for a 2200 rated puzzle, shouldn't that be lower rated then? 
• Puzzle (#1176284). This puzzle is rated 1046, but I found it to be not an easy one to solve. Again, I wasn't alone because this puzzle has around ~ 22% solve rated. After 50k+ attempts.

Are puzzle ratings re-calibrated from time to time or is this just how they are rated? I remember there was an option to give feedback on puzzles, but I don't see that anymore. Or maybe I'm mistaken. Is there any benefit in adding comments on puzzles?

Puzzles generally get a seed rating and then get modified based on members pass/fails and are treated like game against the member puzzle rating vs the puzzles rating.

I think after a certain number of solved the rating locks but staff will occasionally set a new rating if warranted.

These both have been rerated