Consecutive QPEs intensity ratio and recurrence time correlation. The ratio between the intensity of consecutive QPEs is shown as a function of the recurrence time between them (normalised to the sum of consecutive long and short intervals T_sum). The horizontal line (N_i /N_i + 1 = 1) separates events where strong QPEs precede weak ones (upper half of the figure), from those where weak QPEs precede strong ones (lower half). The vertical line separates short from long recurrence times. The (red) dotted line show the best-fitting linear relation between the two quantities.