condition mean min max ZT0-3 18.267200000000003 18.267200000000003 18.267200000000003 ZT4-7 15.0548 15.0548 15.0548 ZT8-11 13.759699999999999 13.759699999999999 13.759699999999999 ZT12-15 14.23935 14.23935 14.23935 ZT16-19 16.964100000000002 16.964100000000002 16.964100000000002 ZT20-23 14.875399999999999 14.875399999999999 14.875399999999999