condition mean min max ZT0-3 3.444795 3.444795 3.444795 ZT4-7 2.84201 2.84201 2.84201 ZT8-11 2.9943850000000003 2.9943850000000003 2.9943850000000003 ZT12-15 4.20852 4.20852 4.20852 ZT16-19 4.869975 4.869975 4.869975 ZT20-23 4.138045 4.138045 4.138045