condition mean min max ZT0-3 2.90462 1.75309 4.02972 ZT4-7 9.529565 9.529565 9.529565 ZT8-11 34.6439 34.6439 34.6439 ZT12-15 12.8256275 7.855705 17.79555 ZT16-19 7.275415000000001 7.275415000000001 7.275415000000001 ZT20-23 4.720165 4.720165 4.720165