condition mean min max ZT0-3 7.56582 7.56582 7.56582 ZT4-7 6.54308 6.54308 6.54308 ZT8-11 5.4506049999999995 5.4506049999999995 5.4506049999999995 ZT12-15 7.731489999999999 7.731489999999999 7.731489999999999 ZT16-19 8.402435 8.402435 8.402435 ZT20-23 6.74716 6.74716 6.74716