How Many Developers Are There In The World?

I have always been curious over the number of developers in each country. Recently, out of a need to present this statistics for my work, I went deeper to search for an answer.

StackExchange provided me with data for a few countries. For example, US has a population of 300 million, and has 1 million programmers (that is 0.33%). 

I took a lower figure and estimated that around 0.1% of a population are active developers who work on web/mobile. With that, I estimate the number of developers in each country as such:

<td valign="top" width="133">
  <strong>Population</strong>
</td>

<td valign="top" width="219">
  <strong>No. of developers (0.1%)</strong>
</td>

<td valign="top" width="133">
  300 mil
</td>

<td valign="top" width="219">
  300,000
</td>

<td valign="top" width="133">
  61 mil
</td>

<td valign="top" width="219">
  61,000
</td>

<td valign="top" width="133">
  127 mil
</td>

<td valign="top" width="219">
  127,000
</td>

<td valign="top" width="133">
  5 mil
</td>

<td valign="top" width="219">
  5,000
</td>

<td valign="top" width="133">
  7 mil
</td>

<td valign="top" width="219">
  7,000
</td>

<td valign="top" width="133">
  22 mil
</td>

<td valign="top" width="219">
  22,000
</td>

<td valign="top" width="133">
  1,330 mil
</td>

<td valign="top" width="219">
  1,330,000
</td>

Country

US

UK

Japan

Singapore

Hong Kong

Australia

China

Quora also provided me a good answer, adding that around 10% of developers specialize in mobile development. That estimate does relate to the 40,000 iOS and 10,000 Android developers reported in appstorehq in 2010.