condition mean min max ZT0-3 0.6938596666666667 0.0 1.20004 ZT4-7 0.575438 0.575438 0.575438 ZT8-11 0.6893475 0.6893475 0.6893475 ZT12-15 0.830544 0.54513 1.115958 ZT16-19 1.673225 1.673225 1.673225 ZT20-23 1.0513165 1.0513165 1.0513165