I do not know the exact figures, but my guess is that India would also quality for upto 50% citizens under 29 years, given that 65% of its citizens are under 35 years.
There are nothing such happening in India right now, which you can call unrest or riots. India has huge population, more than 128 million as we speak, which is equal to the sum of the whole of Europe and North America.
So, some incidents are bound to happen, when you are talking about as large numbers as these. My guess is that if you include all incidents of those above mentioned continents, they also will be quite close to their Indian counterparts.
Secondly, if you look back at the history, there was huge unrest and riots in the US some decades back, when black movement was going on.
Does that mean that US was also facing young bulge at those times? My guess is not. Those particular circumstances lead to unrest, not the age of its citizens.
I have not looked at the stats, but again my guess is that there must be this young bulge in the US also sometime around a century back. But, US progressed more during those years. China also must have passed through this phase 3 - 4 decades back.
The more rational deduction of this young bulge should be that, if a country has more young citizens, it will gather more speed in which direction it is moving already, whether that is progress or regress. It would be wrong to conclude that young bulge is dangerous by default.
Lastly, this gentleman has taken 29 years as a benchmark because that is almost the world median age, 29.6 to be precise.
With love,
Sanjay