Concerns about worldwide growth have also increased the appeal of U.S. bonds as a safe-haven.

Those earlier auctions led to surprising results that have increased the appeal of this Gulf's areas.

That has increased the appeal of dollar assets, especially against another low-yielding currency such as the yen.

That has only increased the appeal for Pioneer's genetically modified seeds, which help farmers fight insects and boost yields, among other benefits.

ATP said a "golden generation of players" and a global platform of tournaments had increased the appeal of the game.