condition mean min max ZT0-3 5.425115 5.425115 5.425115 ZT4-7 3.9287900000000002 3.9287900000000002 3.9287900000000002 ZT8-11 3.6116099999999998 3.6116099999999998 3.6116099999999998 ZT12-15 3.964835 3.964835 3.964835 ZT16-19 4.26771 4.26771 4.26771 ZT20-23 5.69686 5.69686 5.69686