<prompt> Translate the following text to SwahiliThe volume of letters sent by non-households or nonhousehold originated mail can also be calculated from Table 1 by adding NHH-to-HH and NHH-to-NHH volumes.  <response>: Kiasi cha barua zilizotumwa na barua zisizo za nyumbani au barua zisizo za nyumbani zinaweza pia kuhesabiwa kutoka kwa Jedwali 1 kwa kuongeza kiasi cha NHH-to-NHH na NHH-to-NHH. 