According to the International Residential Code, year 2003, the maximum riser height shall not exceed 7 3/4 inches and the minimum tread depth is 10 inches. All measurements are to be withing 3/8 of each other.
You have a steep rise due to the limited space available. How tall are your steps? 7 1/2 inches is a really nice, comfortable step, but you could get away with 8 inches if you really had to.
How long are you steps? This length determines how far out your stairs will protrude. I just build a stairway with 8 inch steps. No code to worry about, and it lined up perfectly with the small space I have.
In some older homes, I've seen the steps smaller then the rise. Especially in old mansions with servents stairs in the back someplace.
The problem with small steps is coming down. It becomes real easy to slip on a small step and get hurt. 8 inches is way under code, but the minimum I'm comfortable with.
Eddie