Former first lady Michelle Obama’s Becoming is on track to become the most successful memoir in history, her publisher said. The book has sold almost 10 million copies, Bloomberg reports.

Bertelsmann SE, which owns Penguin Random House, said the memoir helped lift its total sales to $20 billion, the highest since 2007.

“Penguin Random House in 2017 agreed to pay a reported $65 million to publish separate books from Barack and Michelle Obama,” Bloomberg reports.

“The deal extended a relationship with the publisher that stretched back to when the two-term former president was still an Illinois senator.”