condition mean min max ZT0-3 4.25 4.25 4.25 ZT4-7 3.6 3.6 3.6 ZT8-11 3.0999999999999996 3.0999999999999996 3.0999999999999996 ZT12-15 7.1 7.1 7.1 ZT16-19 11.2 11.2 11.2 ZT20-23 5.5 5.5 5.5