$875 million would pay the salaries of 11,666 air traffic controllers for a decade at that wage.

You’re off by a factor of 10 here. It’s either a year of wages for 11666 controllers or 10 years of wages for 1166 controllers.

Do you really need signing if you’re using HTTPS though?

TBF everyone in school learn to start counting at 1, then they unlearn that in programming. There are also some objective reasons to use 0-based indexing https://www.cs.utexas.edu/users/EWD/transcriptions/EWD08xx/EWD831.html