Read this: Ultimately, Lee spent over two and a half years writing To Kill a Mockingbird. The book was published on July 11, 1960. After rejecting the "Watchman" title, it was initially re-titled Atticus, but Lee renamed it "To Kill a Mockingbird" to reflect that the story went beyond just a character portrait. The editorial team at Lippincott warned Lee that she would probably sell only several thousand copies. In 1964, Lee recalled her hopes for the book when she said, "I never expected any sort of success with 'Mockingbird.' ... I was hoping for a quick and merciful death at the hands of the reviewers but, at the same time, I sort of hoped someone would like it enough to give me encouragement. Public encouragement. I hoped for a little, as I said, but I got rather a whole lot, and in some ways this was just about as frightening as the quick, merciful death I'd expected." Instead of a "quick and merciful death", Reader's Digest Condensed Books chose the book for reprinting in part, which gave it a wide readership immediately. Since the original publication, the book has never been out of print.

How long did Lee spend writing the book?
What is the answer? (If it cannot be answered, return "unanswerable")
over two and a half years