condition mean min max ZT0-3 22.5 22.5 22.5 ZT4-7 9.3 9.3 9.3 ZT8-11 9.8 9.8 9.8 ZT12-15 6.050000000000001 6.050000000000001 6.050000000000001 ZT16-19 17.55 17.55 17.55 ZT20-23 3.2 3.2 3.2