You misunderstood the post. It doesn't claim that 62% of the millionaires are from Asia, which is plain wrong. What the post says is that 62% of the NEW millionaires are from Asia.

Here is the distribution of high-net worth individuals (i.e wealth more than $1 million):

Total population - 12 million

North America -    3.73 million (wealth $12.7 trillion)
Asia-Pacific   - 3.68 million ($12.0 trillion)
Europe - 3.41 million ($10.9 trillion)
Latin America - 0.52 million ($7.5 trillion)
Middle East    - 0.49 million ($1.8 trillion)
Africa - 0.14 million ($1.3 trillion)

Out of the 3.68 million HNW in Asia, 1.9m are in Japan, and 0.643m in China.