condition mean min max ZT0-3 9.698195 9.698195 9.698195 ZT4-7 4.72336 4.72336 4.72336 ZT8-11 6.928985 6.928985 6.928985 ZT12-15 12.18235 12.18235 12.18235 ZT16-19 14.313749999999999 14.313749999999999 14.313749999999999 ZT20-23 15.04785 15.04785 15.04785