Thanks all.
aj_, I've thought about that, but don't want another account or to worry about where AmEx is accepted.
I'm going to say I'm self-employed [I'm an investor--yeah, that's it], so my employer is n/a. I'm going to say I'm making 25K, which isn't too scary low for a single person with no mortgage and which I could also afford, though I'll probably spend less than 19K. I won't worry about using a round number for the income.
(In my case, I'm going to be living off my savings and Roth IRA contributions until I start collecting my pension in three years, so most of it's not taxable--and 4% of my investments, ~6K, is too low a figure to use. Last year I made 42K at multiple jobs; this year it will probably end up being a little more than half that.)