Important to note there is no single, publicly accessible source for the total sales figures for a specific title. Figures reported in Publisher's Marketplace are not necessarily accurate.
Ingram is a wholesaler, so its figures don't include shipments to or sales of the big box stores (Walmart, Costco), or any other market that gets its books from another source.
Depending on the publisher, the author of a book may have very accurate numbers (in advance of royalty statements) from the major markets, which publishers track. Some houses share these numbers with the author, and some don't.
Royalty statements provide the author with figures of earnings through the reporting period, though "how well" a book actually did is difficult to determine until several reporting periods (a couple of years) have passed. And, even then, if the author's backlist continues to rack up sales, the book will continue to earn throughout a lifetime that can, with luck, last a decade or longer.