condition mean min max ZT0-3 22.032775 22.032775 22.032775 ZT4-7 24.833619499999998 24.833619499999998 24.833619499999998 ZT8-11 21.803002 21.803002 21.803002 ZT12-15 20.596280999999998 20.596280999999998 20.596280999999998 ZT16-19 20.8450985 20.8450985 20.8450985 ZT20-23 24.3364135 24.3364135 24.3364135