condition mean min max ZT0-3 19.243000000000002 19.243000000000002 19.243000000000002 ZT4-7 13.9837 13.9837 13.9837 ZT8-11 13.184149999999999 13.184149999999999 13.184149999999999 ZT12-15 14.3017 14.3017 14.3017 ZT16-19 18.99765 18.99765 18.99765 ZT20-23 18.90385 18.90385 18.90385