rent increase law?

I have a question on rent increase law.
I recently saw some related topics on how much the landlord can increase the rent. There is a Annual Allowable Increase Amount.
I searched some web site, on http://www.sfgov.org/site/rentboard_page.asp?id=3683
It says it's 1.7% for last year.
My situation is: we rented a townhouse for $1600 the first year, then after 1 year 2 months, it was 2 months after the lease expires. It means we are on month-by-month rent at that time. The landlord sent us a notice saying they are going to increase the rent to $1800.
After negotiation, we signed the contract for monthly rent at $1750.
It might be too late to ask now. But for my future benefit, I would like to know if it exceeded the annual allowable increase? If it is the case and the landlord refused to reduce the rent, our only choice is to move out? We can not sue him in the small claims court?
Thanks!