Yearly International Sunspot Number S¹ for cycles 12 to 23 as a function of the mean unsigned latitude of the sunspots each year. The line colors indicate the different cycles. The thin black curve is an approximate fit to the declining phase: S = 25λ_c−200. Error bars on the left side indicate standard deviations of λ_c from the Gaussian fitting procedure carried out for each year; the maximum value is shown in red while the mean over all years is given in black.