Which genre of books sells most? I am particularly interested to see how biographies and autobiographies fare?

i dont know but mainly fiction that said autobiographies and biographies can sell well if you go by books like Angelas Ashes and its sequels and they are selling well since Frank McCourt has died a month or two ago, and other well known peoples biographies for example long walk to freedom which is Mandelas biographies is pretty good. i also enjoyed the Dalai Lamas autobiography. the more well known the person and the more influential they are can determine sales as well, but overall fiction tends to sell the highest and that covers paranormal young adult childrens and non fiction such as history historical biographies have become popular lately since shows like the Tudors came out everyone wants to know more about henry the eighth and his wives. and paranormal fiction and scifi is experiencing a boom as well hope i helped !!