They disclose its second place + 0.01, but the article says they lied and raised it by 15%.

“Google’s advertising auctions require the winner to pay only a penny more than the runner-up. In 2016, the company discovered that the runner-up had often bid only 80% of the winner’s offer. To help eliminate that 20% between the runner-up and what the winner was willing to pay, Google gave the second-place bidder a built-in handicap to make their offer more competitive, Whinston said, citing internal emails and sealed testimony by Google finance executive Jerry Dischler earlier in the case.”