Correlation between the yearly values of the 10.7 cm radio flux and the four other radio fluxes. Left column: scatterplots between 10.7 cm and the four radio fluxes (colored crosses), together with the corresponding best-fit lines (black). Right column: differences between the four radio fluxes and the correlated 10.7 cm radio flux normalized by the corresponding radio flux. Best-fit lines (black solid lines) and lines with slopes that are two standard deviations above or below the best-fit line slope (two blue dashed lines) are also included. Order of radio wavelengths and their colors are the same as in Fig. 1. (F10.7 is naturally omitted.)