12 aimed shots a minute was the minimum requirement for archers wishing to join the bow companies of the Agincourt campaign, not sure how much standards were lowered half a century later. The maximum for skilled archers could be double that.
But since it was common for longbows to be countered with crossbows (or other longbows) then what often happened was that the battle would begin with a long range duel at extreme range until the arrows ran out. Agincourt was a bit of a freak because the crossbowmen had left their pavisses behind and had wet strings, so they didn't stand a chance against the English and Welsh bowmen who had kept their strings dry.

