With regards to the "grain of salt", scarletpeaches . . . I'm noticing there is a big difference between what counts as "finished" among posters. So a grain of salt does seem wise.
It took me about 7 months to do a first draft. But I think that's kind of a meaningless number. People who write professionally can devote 8 to 12 hours a day to writing, while those of us who are caring for small children can only grab an hour a day, sometimes even less than that. (Sometimes I sit down to write at the end of the day and just fall asleep sitting there). So how long it takes you to finish a novel depends a lot on how motivated you are, how much time you can devote to it, and how much energy you have remaining after all your other daily tasks are complete. If I had even one full day a week that I could devote to just writing, I'm pretty sure I could turn out a novel every couple of months.