What percent of Kenya's population speaks English?

The Cambridge Encyclopedia of the English Language estimates English-speakers in Kenya to constitute 9 percent of the population of 25 million, or about 2.24 million people, while the BBC World Service estimates 3.4 million adult English speakers there. And a spokesman at the Kenyan embassy in Washington recently estimated that 80 percent of the nation's 23 million population knows at least some English, which would mean 18.4 million people.