Sunspot number as a function of time. The blue curve gives the actual sunspot number and the red curve the monthly average. The variation in the Sun’s activity cycle is easily visible. The green shaded area marks the sequence of CRs we used for this study. The blue and red shaded areas mark sequences of CRs we investigated for comparison, the blue one also happens during the quiet time of the Sun while the red one happens during the active Sun. Data taken from Royal Observatory of Belgium (2016).