Customs duties for bringing new Iphones as gifts for friends

People. I will be visiting Ethiopia soon. A couple of my friends have asked me to buy new iPhones for them, which are way cheaper where I am from. I told them that perhaps it may eventually end up costing them the same (after customs duties). They don't know if I would need to pay any duties at all. I'm not planning to get into trouble with the authorities by not declaring these phones, if required by law to do so. Can someone here tell me if 1) I am needed to declare these phones and 2) What's the custom duties % when bringing new phones into the country?