No, it's YoY, meaning from May 2021 - May 2022 prices rose 7%. From June 2021 - June 2022 prices rose 9%.

People are getting confused by this

The YOY is 7-9%

The monthly change is around .5-.8% , so nowhere close to 16%

16% inflation in 2 months would be very, very bad!

Putting aside the fact that the numbers are year over year and not month to month, that isn't how percentage increases work. If you have a quantity that goes up 9% and then goes up another 7%, it has then gone up (1.09 * 1.07) - 1 ~= 16.63%. This is how compounding works. In a single period, it doesn't make much of a difference, as you can see, it's barely more than 16%, but over many periods, compounding results in much greater cumulative growth than if you simply added the increases together.