condition mean min max ZT0-3 30.984700000000004 26.472250000000003 35.497150000000005 ZT4-7 9.37654 9.37654 9.37654 ZT8-11 7.895885 7.895885 7.895885 ZT12-15 0 0 0 ZT16-19 32.792550000000006 32.792550000000006 32.792550000000006 ZT20-23 37.4129 37.4129 37.4129