condition mean min max ZT0-3 18.156033333333333 11.70735 23.99815 ZT4-7 11.763480000000001 11.763480000000001 11.763480000000001 ZT8-11 15.530249999999999 15.530249999999999 15.530249999999999 ZT12-15 23.99065 17.254399999999997 30.7269 ZT16-19 27.249200000000002 27.249200000000002 27.249200000000002 ZT20-23 29.5831 29.5831 29.5831