Facebook’s CEO Mark Zuckerberg and his wife, Priscilla Chan, have been crowned the most generous Americans in 2013 — after they donated 18 million Facebook shares valued at more than $970 million to the Silicon Valley Community Foundation, the Associated Press reports.

An annual ranking of the top 50 donors in America, produced by publication The Chronicle of Philanthropy, showed that the wealthy donated a total of $7.7 billion last year — four percent more than in 2012. Aged below 30, Zuckerberg and his wife have become the youngest ever philanthropists to occupy the top position.

The Chronicle of Philanthropy notes that charities are “eagerly awaiting” further news on how Zuckerberg and his wife will allocate the 36 million Facebook shares they have donated to the Silicon Valley non-profit organization over the past two years, which is worth about $1.5 billion.

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