condition mean min max ZT0-3 6.3 6.3 6.3 ZT4-7 12.0 12.0 12.0 ZT8-11 3.0999999999999996 3.0999999999999996 3.0999999999999996 ZT12-15 18.4 18.4 18.4 ZT16-19 21.1 21.1 21.1 ZT20-23 25.25 25.25 25.25