The Marauders hired by the Galaxy to do the Fake Alien War on earth to prevent human extinction the next few hundred years:

Have a base on Ganymede one of Jupiter's moons. They have protection by the Galactic Time Guard from attack by anyone during the next few hundred years or however long the galaxy wants to hire them to prevent human extinction. During this time it is thought that 7/8 of the population of mankind will pass away from wars, global climate changes etc.

However, those that will remain and survive all that is coming will be more like Americans in the 1600s to late 1800s than anything else, sort of like the pioneers of old you might see in cowboy movies. This is likely the kind of person that will survive often what is coming to all over the world.

Whatever country you live in expect about 1/8 of the population numbers to survive this century until 2100. It could be less than this given all present variables in place including wars, droughts, and major global climate changes worldwide this century and after. 

So, if you are calculating and interested in math divide the present population of your country or city or state by 8. This is what we all likely are facing now for several hundred years or so.