A study has pinpointed the average writer’s peak. “The average age of writers who topped the hardback fiction section of the New York Times Bestseller List from 1955-2004 was 50.5 years. Of the 350 authors who saw their novels reach the number one spot over the past 50 years, Francoise Sagan was the youngest with Bonjour Tristesse, published at the age of 19 in 1955. By comparison, Agatha Christie was the oldest author to top the list, with her novel Sleeping Murder, published shortly after her death at the age of 85.”