>Friendship is set when a Pokémon is brought under a Trainer's control; i.e., it has a value of 70 when a Pokémon is captured from the wild, and reset to 70 when a Pokémon is traded from another game.
Return's base power would be 28(Friendship/2.5) and for Frustration it would be 74((255-friendship)/2.5.
Source
Hope I helped!