<prompt> Translate the following text to SwahiliWithin the U.S. it is surprising that the average postal density of the bottom quartile of routes ranked by cost is lower than the postal density for the rural routes serving the least densely settled 10 percent of the population 50 versus 89.  <response>: Katika nchi za Marekani, ni ajabu kwamba wastani wa posta density ya chini quartile ya njia kwa gharama ni chini ya posta density kwa njia za vijijini kuwahudumia chini densely makazi asilimia 10 ya idadi ya watu 50 dhidi ya 89. 