Are you comparing the fans in the quote you used? If so you are looking at two different Noctua fans. The fans in the image you posted are the NF-A12x25 PWM whereas the data from your quote from what I said is pulling data from the NF-F12 iPPC-2000 3-pin fans. SO the data data would be different because of the different fans.
All the data on my spreadsheet is still up-to-date even though this post is older. All the data on that spreadsheet is pulled directly from the Noctua spec pages. I have notes on it as well to make sure that the data I used in that spreadsheet is recorded with the assumption that no L.N.A. from Noctua is being used.
My final note is that without the direct source to that graph you shared I don’t know how they were testing that fan. The chart does not say what the testing environment was so this is pretty much comparing apples to oranges.