I remember reading somewhere that $5000 a year was some kind of median for
professionally published writers. But this was a number of years ago, and I don't know if it was averaging people who sell a short story to a pro market (nowadays defined as $0.05 a word or better) now and again in with people who have actually published novels. I also don't know whether they were averaging people who may have just sold one pro market story or even one novel ever, or if there is some minimum level of ongoing publication activity they were using.
Obviously, a distribution of writer earnings is going to have a cluster of tightly clumped numbers to the left of the median (whatever it currently is), because you can't make less than 0 a year as a writer (well, okay, with self publishing and its associated expenses, actually you can now
). But there are a tiny handful of writers who make vast amounts of money from their writing, so the distribution of author incomes will not be bell shaped.
I think it is safe to say, though, that the majority of published writers, even novelists, do not support themselves solely by their writing. Some are lucky enough to have spouses who make enough to subsidize their income, or to have professions that allow them to work part time and still make enough to get by. But a lot of writers struggle with trying to eke out at least a couple of hours of writing time each day around the normal demands of full time jobs and family obligations.
In the end, it's something people do because they love to do it. Supporting oneself with one's writing at any level, let alone a reasonably comfortable middle class income, is not something most writers get. But that doesn't mean it shouldn't be something one should want or hope for. Just remember to set realistic and reasonable goals for your writing at this stage of the game (goals like writing a certain amount of time each day, getting a certain number of stories written and submitted, finishing a novel etc).
17,000 is a reasonably modest goal and so is more attainable, certainly, than someone who has a house and a mortgage and two kids headed for college and who needs to replace the income from a 75,000 a year job. But as with anything else, you have to focus on setting goals you can control (i.e. writing as much and as well as you can), because you have far less control over who buys your writing and how much they'll pay you for it if they do.
