Approximately, how long does it take to write a novel?

With two novels complete, (and two abandoned) I am working on a third which I intend to finish in two years rather than the ten and six years taken for the first and second ones.

This may seem much longer than other answers.

I work creating technical training 40 hours a week, which leaves me with less energy for creative writing. I start with a basic outline. Still my novels tend to be over 100,000 words, so I must trim them back to a reasonable length. My typing speed is slow and I’ve tried narrating. However, the amount of additional edits required make this method just as slow.