condition mean min max ZT0-3 3.9024799999999997 3.3773999999999997 4.42756 ZT4-7 9.095455 9.095455 9.095455 ZT8-11 21.0119 21.0119 21.0119 ZT12-15 0 0 0 ZT16-19 9.289645 9.289645 9.289645 ZT20-23 6.529495000000001 6.529495000000001 6.529495000000001