Mach number derived from radio (Mradio) plotted against that from the ICM temperature. The error bars are only statistical and at the one sigma level. Red and blue crosses are this work, but with previous and new radio result (van Weeren et al. 2010; Stroe et al. 2014b). Grsy crosses show the previous our results (Akamatsu & Kawahara 2013). Note: Stroe et al. (2014a) does not give information about the southern relic because the low flux. Therefore the result of the new radio analysis is only available for the northern relic. However, similar to the northern relic case, the Mach number of the southern radio relic is expected to drop.