In many countries, such as India, there is actually a rise in women in Computer Science, probably more to do with the fact that in most cases they start off on an equal footing to boys in terms of exposure to computers pre-college and secondly due to the lucrative (in relative terms) job prospects and non-manual nature of the work.

The trends there seem to be following the early trends of the graph here (but in a more condensed timeframe), and it will be interesting to see how it continues.