Trapped fraction as a function of the central field strength of the internal magnetic field for the models 2A (top), 2B (middle), and 2C (bottom). Different colors indicate different combinations of the frequency ω and the spherical degree l (see legend). The dotted lines mark the corresponding central critical field strength. The error bars are determined by the uncertainty of f_T (see Eq. (12)). The line connecting the symbols is a fit to the trapped fraction presented in Sect. 3.2.