condition mean min max ZT0-3 6.8755033333333335 5.378825 9.125005 ZT4-7 4.976324999999999 4.976324999999999 4.976324999999999 ZT8-11 2.113235 2.113235 2.113235 ZT12-15 3.3525125 2.8489649999999997 3.8560600000000003 ZT16-19 6.60391 6.60391 6.60391 ZT20-23 5.76675 5.76675 5.76675