condition mean min max ZT0-3 14.292366 14.292366 14.292366 ZT4-7 13.000180499999999 13.000180499999999 13.000180499999999 ZT8-11 13.5085545 13.5085545 13.5085545 ZT12-15 12.4314785 12.4314785 12.4314785 ZT16-19 12.913889000000001 12.913889000000001 12.913889000000001 ZT20-23 12.8156045 12.8156045 12.8156045