condition mean min max ZT0-3 5.68621 4.832789999999999 6.829935 ZT4-7 4.872185 4.872185 4.872185 ZT8-11 5.9384049999999995 5.9384049999999995 5.9384049999999995 ZT12-15 7.6623275 7.602869999999999 7.721785000000001 ZT16-19 8.39313 8.39313 8.39313 ZT20-23 8.66045 8.66045 8.66045