condition mean min max ZT0-3 22.968577 22.968577 22.968577 ZT4-7 22.132272 22.132272 22.132272 ZT8-11 24.8491365 24.8491365 24.8491365 ZT12-15 20.905566 20.905566 20.905566 ZT16-19 25.556359999999998 25.556359999999998 25.556359999999998 ZT20-23 22.8628155 22.8628155 22.8628155