<prompt> Translate the following text to SwahiliThis increase in the volume of bill mail offsets more than half of the decline in the volume of payment mail allowing billpayment mail to decline by only 1.1 billion pieces between 1990 and 1996.  <response>: Ongezeko hili la kiasi cha barua ya bili linagharimu zaidi ya nusu ya kupungua kwa kiasi cha barua ya malipo, na kuruhusu kiasi cha barua ya bili kupungua kwa vipande 1.1 kati ya 1990 na 1996. 