<prompt> Translate the following text to SwahiliThe fourth row, labeled Subtotal shows the First-Class household mail as the sum of mail in the above three sectors.  <response>: Safu ya nne, iliyoitwa Subtotal inaonyesha barua ya kaya ya Darasa la Kwanza kama jumla ya barua katika sekta tatu zilizotajwa hapo juu. 