Teacher pay of the day was probably pretty closely related to where they taught. 1900s northern Michigan was probably not a cash rich place. My grandmother grew up on a farm like nearly everyone else they knew.
I wondered if there was also a jump from 1900 to 1910 maybe. And yes, I suspect it depended greatly on where it was, because I’m pretty sure the local town contracted the teacher and decided what they would pay, or what arrangements they would make.