condition mean min max ZT0-3 4.160163333333333 2.10023 5.94649 ZT4-7 1.35859 1.35859 1.35859 ZT8-11 2.56413 2.56413 2.56413 ZT12-15 5.3904974999999995 4.79149 5.989504999999999 ZT16-19 7.869095 7.869095 7.869095 ZT20-23 8.620415 8.620415 8.620415