Distribution of observed ratio of [O iii] λ4959/[O iii] λ5007 in 0.10 <z< 0.15 sample for S/N_line> 7. The solid arrow corresponds to the theoretical ratio of 1/2.98 (Storey & Zeippen 2000). The median and the 68th percentiles are represented as the dashed and dotted red lines, respectively. The median flux ratio is 0.333 with a standard deviation of 0.07, within 1 per cent of the theoretical value.