vs. Q(He⁰)/Q(H⁰) for individual stars assumed in this work based on non-LTE blanketed CoStar models (Schaerer & de Koter 1997) (solid line), Mas-Hesse & Kunth (1991) relations based on Mihalas (1972) non-LTE unblanketed models (red dotted line) for stars with luminosity class V and I (hexagons and triangles respectively), Martins et al. (2005) relations based on CMFGEN (Hillier & Miller 1998) non-LTE spherical extended line-blanketed models (blue short-dashed line) for V and I stars, and Smith et al. (2002) relations based in WMbasic (Pauldrach et al. 2001) computations (orange long-dashed line).