"Going by general patterns of people leaving and arriving..."

She pulls a pair of very dark sunglasses out of her pocket - cripes, these surroundings are terrible, they make it really hard to think - and concentrates to activate the filter, and... yeah, better. Okay. Let's see...

"One or two years? It seems like at most 10 percent of people are still here, five or less if we apply a conservative estimate, and considering that people sometimes return after having been gone for a while..."