condition mean min max ZT0-3 14.3 14.3 14.3 ZT4-7 1.9 1.9 1.9 ZT8-11 16.099999999999998 16.099999999999998 16.099999999999998 ZT12-15 4.2 4.2 4.2 ZT16-19 23.25 23.25 23.25 ZT20-23 8.55 8.55 8.55