condition mean min max ZT0-3 7.25 7.25 7.25 ZT4-7 14.8 14.8 14.8 ZT8-11 25.0 25.0 25.0 ZT12-15 7.35 7.35 7.35 ZT16-19 5.6000000000000005 5.6000000000000005 5.6000000000000005 ZT20-23 13.15 13.15 13.15