condition mean min max ZT0-3 31.28105 21.94695 36.47085 ZT4-7 21.147100000000002 21.147100000000002 21.147100000000002 ZT8-11 14.852450000000001 14.852450000000001 14.852450000000001 ZT12-15 20.3507 19.6941 21.0073 ZT16-19 20.77065 20.77065 20.77065 ZT20-23 34.71325 34.71325 34.71325