condition mean min max ZT0-3 3.08933 3.08933 3.08933 ZT4-7 2.107335 2.107335 2.107335 ZT8-11 2.017405 2.017405 2.017405 ZT12-15 2.445545 2.445545 2.445545 ZT16-19 3.0006 3.0006 3.0006 ZT20-23 2.8468999999999998 2.8468999999999998 2.8468999999999998