China: 1,349,585,838 people (per the Census again)
South Korea: 48,955,203
North Korea: 24,720,407
Sri Lanka: 21,675,648
… which adds up to a grand total of 3,637,830,357, or roughly 51.4 percent of the global population. (The circle also appears to include parts of Russia and Pakistan, which I haven't included, and may have cut off a bit of northwest China.)
Asia’s population dominance is not a new thing: According to this neat NPR video on population growth, "most people lived in China, India and the rest of Asia" around the year 1000, too. But since population growth has gotten so fast, Asia is now expanding on an entirely different scale. By 2050, the U.N. predicted last year, 3.3 billion people will live just in Asia's cities.