condition mean min max ZT0-3 27.04436666666667 24.66685 29.87375 ZT4-7 22.323900000000002 22.323900000000002 22.323900000000002 ZT8-11 20.32645 20.32645 20.32645 ZT12-15 29.287325000000003 28.13335 30.441300000000002 ZT16-19 30.8209 30.8209 30.8209 ZT20-23 35.124399999999994 35.124399999999994 35.124399999999994