Did I ask this question previously re: Renters rights regarding annual increases?

[Grasswire2]

Apologies if I have already asked this.

Just got another letter from landlord about "the annual monthly rent increase of x00..."

My rental agreement does not mention an increase in monthly rent imposed annually. I have lived here fifteen years; this annual increase began five years ago. My rent is now nearly double what it was agreed to in the contract.

Maintenance isn't great -- there are many things that need repair or replacement. BUT the location is fantasticc and neighbors are wonderful.

Is this lawful?.To begin imposing an annual increase though not stipulated in rental contract?

Thank you in advance for input.