condition mean min max ZT0-3 11.1386 11.1386 11.1386 ZT4-7 7.667854999999999 7.667854999999999 7.667854999999999 ZT8-11 7.4259450000000005 7.4259450000000005 7.4259450000000005 ZT12-15 12.099499999999999 12.099499999999999 12.099499999999999 ZT16-19 16.6198 16.6198 16.6198 ZT20-23 17.0656 17.0656 17.0656