Histograms showing the distribution of the occurrence of (a) all CMEs, (b) all type II bursts, (c) all type II bursts that were accompanied with white-light CMEs, and (d) all type II bursts without any association with a CME from January 1996, to December 2019. This corresponds to solar cycles 23 and 24. The dashed red profile shows the Gaussian fit to the histograms. The two peaks of these Gaussian peaks correspond to the solar maxima in the respective solar cycles.