condition mean min max ZT0-3 3.891783333333333 2.248875 4.918464999999999 ZT4-7 1.338865 1.338865 1.338865 ZT8-11 1.0771935 1.0771935 1.0771935 ZT12-15 2.218235 1.95862 2.47785 ZT16-19 2.4293750000000003 2.4293750000000003 2.4293750000000003 ZT20-23 3.857525 3.857525 3.857525