There has been increasing talk about the "rise of the nones", but is it really so? Is the "rise of the nones" significative in a global scale?

There has been increasing talk about the "rise of the nones", but is it really so? Is the "rise of the nones" significative in a global scale?
On a 40 year time scale, the unaffiliated are projected to [de]convert ~20 times more than the most converting religion (Islam). But the unaffiliated will still decrease in percentage of the world population due to the the indoctrination of the sons and daughters of religious people, being the birth rate the only thing sustaining the growth of religion.

http://www.pewforum.org/2015/04/02/religious-projections-2010-2050/