condition mean min max ZT0-3 3.342545 2.86 3.82509 ZT4-7 6.265124999999999 6.265124999999999 6.265124999999999 ZT8-11 5.8617799999999995 5.8617799999999995 5.8617799999999995 ZT12-15 0 0 0 ZT16-19 4.920365 4.920365 4.920365 ZT20-23 4.945955 4.945955 4.945955