condition mean min max ZT0-3 8.737176666666667 6.712885 11.822099999999999 ZT4-7 11.59035 11.59035 11.59035 ZT8-11 9.124655 9.124655 9.124655 ZT12-15 20.605625 14.75905 26.452199999999998 ZT16-19 15.0428 15.0428 15.0428 ZT20-23 13.71135 13.71135 13.71135