Evolution of the main parameters in N-body simulation showing the secular evolution of the bar. Rotation curve and main frequencies adopted in the Milky Way-type galaxy model (top left). The bar in the simulation established at about ≈1 Gyr, and due to angular momentum exchange with the dark matter halo later slows down (bottom left), becoming rounder which reflects in the decrease of the bar strength (A₂, top right). Since the bar rotates more slowly the mean location of corotation and the OLR move outward with time (bottom right).