condition mean min max ZT0-3 2.76526 1.77293 3.3020750000000003 ZT4-7 2.944045 2.944045 2.944045 ZT8-11 1.594705 1.594705 1.594705 ZT12-15 3.6439975000000002 3.3858800000000002 3.9021150000000002 ZT16-19 3.1585900000000002 3.1585900000000002 3.1585900000000002 ZT20-23 3.23581 3.23581 3.23581