Sales of Adolf Hitler's Mein Kampf have soared since a special edition of the Nazi leader's political treatise went on sale in Germany a year ago, the German publisher has said. The book, titled Hitler, Mein Kampf. A Critical Edition, outlines Hitler's ideology that formed the basis for Nazism and sets out his hatred of Jews, which led to the Holocaust. The new edition is the first reprint since World War II, released last January after a 70-year copyright on the text expired at the end of 2015. It includes explanatory sections and some 3,500 annotations, and has sold 85,000 copies to the surprise of its publishers. "These sales figures have taken us by storm," Andreas Wirsching, who heads up the publishers, the Institute for Contemporary History (IfZ), told German news agency dpa. "No one could really have expected them," he added. Hitler wrote Mein Kampf, which translates as My Struggle in English, between 1924 and 1926. It was banned by the Allies at the end of World War II. Hitler wrote most of the first, highly autobiographical, volume while incarcerated in Landsberg prison after his failed Munich coup attempt in 1923. After his release, he wrote much of the second volume at his mountain retreat near Berchtesgaden. A bestseller after he became chancellor in 1933, Mein Kampf had by 1945 sold 12 million copies and been translated into 18 languages.