A wedding pic of Zuckerberg and Priscilla Chan/Reuters

Founder and chief executive of Facebook Mark Zuckerberg and his wife have been ranked not just as America's top charity donor in 2013,but also the youngest  according to philanthropists to top the list, according to The

Zuckerberg, 29, and his wife Priscilla Chan gave $990 million to the Silicon Valley Community Foundation, the California charity, in December, with this the couple have become the youngest philanthropist under 30 years to top the publication's annual ranking of the top 10 publicly announced gifts.

" While this year's nearly $1-billion gift from Mr. Zuckerberg and Ms. Chan sets a new record because it comes from philanthropists under 30-the first time donors that young have made the biggest contribution-2013 is also notable because of a strong rebound in the number of gifts of $100-million or more. Fourteen other Americans donated gifts at that level, compared with the 11 who did so last year," The Chronicle of Philanthropy report noted.

Zuckerberg and  Chan ranked No. 2 on the 2012 list of the biggest single charitable gifts for their first substantial contribution to the foundation, some 18 million Facebook shares that were then worth a half-billion dollars.

Stacy Palmer, The Chronicle of Philanthropy editor noted that the rise in large gifts was a sign of the improvement in the economy."I think this is a good sign. I have noticed a lot of non-profits saying their end of year fundraising has gone well, which was not the case in the past few years when it was a real struggle," she said.

After Zuckerberg, the second on philanthropist list was Philip Knight,co-founder of Nike, and his wife, Penelope. The couple have pledged $500-million to Oregon Health and Science University Foundation for cancer research and said the university must match the donation within the next two years to receive all of the money.

The third generous gift was followed by a $350-million pledge from, former Mayor of New York, Michael Bloomberg to the Johns Hopkins University to promote cross-disciplinary studies and financial aid for undergraduate students.

Colleges and universities were the main beneficiaries of large donations in 2013 with 12 of the 15 leading gifts going to higher education.

Top ten Philanthropists of 2013

1. Mark Zuckerberg, Facebook chief executive, $992.2m to Silicon Valley Community Foundation
2. Phil Knight, Nike chairman, $500m to Oregon Health & Science University Foundation
3. Michael Bloomberg, businessman and former mayor of New York, $350m to Johns Hopkins University
4 Charles Johnson, financier, $250m to Yale University for residential buildings
5. Stephen Ross, real-estate developer, $200m to University of Michigan for athletics and the business school
6. Muriel Block, real-estate heiress, $160m to Yeshiva University's College of Medicine
7. John Arrillaga, real-estate developer, $151m to Stanford University
8. Irwin Jacobs, co-founder of Qualcomm, and his wife Joan, $133m to Cornell University
9. Charles Munger, vice chairman of Berkshire Hathaway, $110m to University of Michigan for student housing
10. David Koch, businessman and political activist, $100m to New York Presbyterian Hospital