Why does Mr. Kelly raise the rent by 10%?

Tenant: Yes, I’d like to see—Oh, there you are, Mr. Kelly. Just the one I want to talk to.
Kelly: What can I do for you?
Tenant: I’m Susan Wright, from 227 Green Street. I got this notice in the mail yesterday that you’re raising the rent ten percent. That’ s $30 more. That’s a lot of money every month.
Kelly: Well, the cost of living goes up every day.
Tenant: Yeah, but I called the Bureau of Labor Statistics before I came and they said the CPI increased only three point six percent over last year, so ten percent is a big increase in rent.
Kelly: I don’t know anything about the CPI, but I do know that everything keeps going up. You want heat, don’t you? Well, oil costs more. You want to cook, don’t you? Well, gas costs more. And nobody cleans a building for free. And there are taxes and water and repairs and a hundred other things. I have to pay more, so the tenants have to pay more.
Tenant: Yeah, but last year the increase was only five percent.
Kelly: Look, we’ve spent a lot of money—what’d you say, you’re at 227 Green Sheet—we’ve just put in new smoke alarms...
Tenant: Wall you have to do that by law.
Kelly: Law or no law, it still costs money. And we put a new washing machine in the basement—and law didn’t require that. We put in new mailboxes in January. And...
Tenant: Yeah, but you don’t take care of the apartments. I’ve been complaining about a broken light switch for months.
Kelly: A broken light switch? I didn’t know anything about that.
Tenant: I’ve called this office about it at least three times.
Kelly: I never heard about it. I’ll have someone get on it right away. So, your name is Wright, Number 227? Well, where’s the light switch?
Tenant: In the bedroom.
Kelly: Okay I’ll get it fixed right away.
Tenant: Yeah, okay.