Plot of the total number of spotless days during each solar cycle minimum since 1820, i.e., over the period when the index is available for all days (red curve). For comparison, the monthly average sunspot index R _i is plotted in a reversed vertical scale (green curve), showing the global anticorrelation between spotless days and the global trend in sunspot cycle amplitude. The green horizontal marker lines help us to see that several other minima largely exceeded the last minimum in terms of spotless days, in particular the leftmost one that corresponds to the end of the Dalton minimum. They also show that the four recent minima (19–22) had consistently very low values without equivalent over at least the last 200 years.