condition mean min max ZT0-3 2.9697916666666666 2.621575 3.38915 ZT4-7 2.569965 2.569965 2.569965 ZT8-11 2.686165 2.686165 2.686165 ZT12-15 3.8679300000000003 3.717285 4.018575 ZT16-19 2.731675 2.731675 2.731675 ZT20-23 3.021045 3.021045 3.021045