Example of time evolution of bar length L_bar and corotation radius R_CR (top) and their ratio ℛ = R_CR/L_bar (bottom) for a barred galaxy of ID=333 425 at z = 0. A black dashed horizontal line marks the customary boundary of ℛ = 1.4 between relatively fast and slow bars. While the average evolution of the bar length and the corotation radius is stable, small deviations in both of them make the ratio noisy, which complicates the interpretation of the values of this parameter.