condition mean min max ZT0-3 4.688811666666666 4.03004 5.7354199999999995 ZT4-7 4.266935 4.266935 4.266935 ZT8-11 4.413335 4.413335 4.413335 ZT12-15 5.00038 4.530455 5.470305 ZT16-19 6.635185 6.635185 6.635185 ZT20-23 8.034725 8.034725 8.034725