When the book was released in November of last year, it sold 725,000 copies on its first day and 2 million copies in North America within two weeks, quickly becoming the best-selling book of 2018. It also broke the record of best first-week sales at Barnes & Noble and went on to become a number one seller abroad, including in the U.K. and Germany.

Now it looks like Becoming is on track to become one of the best-selling memoirs—ever. Publisher Penguin Random House announced Tuesday that the book has sold close to 10 million copies to date, across print, digital, and audiobooks globally.

“I’m not aware, in my personal experience with Penguin Random House, that we ever sold 10 million units of a memoir,” Markus Dohle, Penguin Random House’s chief executive told The Wall Street Journal. “We believe this could be the most successful memoir in history,” added Bertelsmann Chief Executive Thomas Rabe. Bertelsmann owns a 75% stake in Penguin Random House.

Becoming is the first in a two-book deal between the Obamas and Penguin Random House. The publishing house reportedly paid $60 million for the deal in 2017, a record for U.S. presidential memoirs. Former President Barack Obama’s memoir is expected to be released later this year, but a formal date has not yet been set.