What is the largest amount you've earned via a single Adsense click?

We have recently noticed a pick up in the ad revenue being spent by various internet companies. Some of the larger internet companies seem to be paying out unusually large amounts per click for rather routine niches.

In our case the largest payout per single click was just under $14. That's right, and there was more than one click from this unit that yielded similar results. Below is an example screenshot I took of one of our top preforming ad units (with unrelated info removed). We even left the title of that ad unit visible to show the routine nature of the niche.