Michelle Obama’s memoir Becoming has become the best-selling hardcover book of 2018.

According to the Washington Post, the former First Lady’s book has sold more than two million copies in all formats in North America within its first 15 days of being out.

Penguin Random House, who published the book, said in a statement that the book has now sold 3.4 million copies in print within the United States and Canada.

Becoming is also the top seller in Great Britain, Germany, France, Italy, Spain, Holland, Denmark, Finland, Norway and Greece. It was published in 31 languages.

Michelle Obama is currently in the midst of a tour promoting Becoming. She is, however, taking off some time to attend the funeral of George H.W. Bush, who passed away on Friday (November 30).