Time-averaged probability density function for the vertical component of the magnetic field at 4 different depths for the statistically-steady, nonlinear dynamo calculation that is illustrated in Fig. 10. The different curves correspond to z = 0 (solid line), z = 0.1 (dash-dotted line), z = 0.5 (dashed line) and z = 0.9 (dotted line). At each depth, the magnetic field has been normalised by the local equipartition field strength, B_eq.