 Guerry is best known for his "Essay on moral statistics of France," presented to the French Academy of Sciences on July 2, 1832, and published in 1833 after it was awarded the in statistics.His presentation, in tables and thematic maps, showed that rates of crime and suicide remained remarkably stable over time, when broken down by age, sex, region of France and even season of the year.Yet, these numbers also varied systematically across departments of France.