How large were the choruses in Aeschylus’s tragedies?

In the development of ancient Greek tragedy, the playwright Aeschylus is credited with reducing the size of the chorus from 50 performers to 12.1

Prior to this innovation, choral performances—which originated as groups of 50 men singing and dancing dithyrambs—dominated early Greek drama. By decreasing the number of chorus members, Aeschylus shifted the focus of the performance, allowing for the introduction of a second actor and placing greater emphasis on the plot and dialogue between characters.12