condition mean min max ZT0-3 13.020976 13.020976 13.020976 ZT4-7 13.1346895 13.1346895 13.1346895 ZT8-11 15.065908499999999 15.065908499999999 15.065908499999999 ZT12-15 12.3407005 12.3407005 12.3407005 ZT16-19 13.291547 13.291547 13.291547 ZT20-23 12.711043499999999 12.711043499999999 12.711043499999999