Four out of 5 world leaders use Twitter, an annual ranking of the use of social media among world leaders by the Digital Policy Council found. The numbers are an increase of 8 percent compared with the number of leaders using the service in 2012, the Washington group said in a release Thursday. The survey also ranks the Top 10 tweeting leaders in the world, placing President Obama No. 1 with 16 million followers added in a year. The biggest Twitter debut for a world leader in 2013, the group said, was Indonesian President Susilo Bambang Yudhoyono, who joined Twitter in 2013 and gained 4.2 million followers in short order, putting him at No. 2 on the list. The biggest jump in Twitter ranking was made by Sheik Mohammed bin Rashid al-Maktoum, prime minister of the United Arab Emirates and ruler of Dubai, who moved from No. 10 in 2012 to seventh place in 2013. China was conspicuous by its absence on the list; none of the country's leaders are on Twitter because the social network is blocked in China.