From top to bottom: evolution of B/H, B/Fe and B/Be. In the first two panels dotted lines indicate primary and secondary evolution. In the bottom panel, the solid curve corresponds to the total ¹¹B production (GCR + ν-nucleosynthesis) and the dotted curve to ¹¹B produced by GCR alone. Data are from: Primas et al. (1999, filled squares), Garcia-Lopez et al. (1999, filled circles), Cunha et al. (2000, asterisks), and Tan et al. (2010, open squares).