Fits to the light curve of the optically thin regime of SN 2008iz at 5 and 22 GHz. β and K₀ (see Eq. (1)) are derived from the fit to the data over the range of 100−1500 days for 5 GHz and 60−1500 days for 22 GHz. The fitted data are shown as filled symbols, while the data not used to fit are shown as open symbols. The MERLIN 5 GHz data were taken from Beswick et al. (2009) and the Urumqi 5 GHz from Marchili et al. (2010). The remaining data are tabulated in Table A.1.