condition mean min max ZT0-3 7.085658333333333 4.210509999999999 9.370355 ZT4-7 3.54012 3.54012 3.54012 ZT8-11 3.417515 3.417515 3.417515 ZT12-15 10.08224 8.26088 11.9036 ZT16-19 9.274944999999999 9.274944999999999 9.274944999999999 ZT20-23 12.1461 12.1461 12.1461