How Many Books do you Have to Sell?

Publishers and authors tend to keep actual numbers under wraps when it comes to print runs and books sold. As a result, new authors are often clueless as to what's normal. I know I was completely lost the first time I saw actual numbers for Goblin Quest. Was my book selling well? Was I going to get dumped if I didn't sell 100,000 books in the first year? How many books did my publisher actually print?

I don't actually know what my print runs have been. I have some guesses, but nothing from