France was, as late as 1800, the most populated country in Europe.
Per wiki(I think it's accurate), in 1816 France had a population of 30,000,000(Comparable to Russia, well above Britain, Austria and Prussia). By 1911 it was only 41,000,000, putting it well below Germany, Austria, Russia and on par with Britain(Below it counting Dominions).
What if France has a modest population growth? Maybe 40,000,000 by the time of the Franco-Prussian War, 60,000,000 by WWI era, 70,000,000 before WWII era? I'm not sure what could have caused this. But it would give France a larger Industrial Base, a larger Army and and more reserves in all of the previously mentioned wars.
How could this have effect French history, European History, and World history?