condition mean min max ZT0-3 12.530066666666666 7.20215 16.53395 ZT4-7 7.85695 7.85695 7.85695 ZT8-11 8.459115 8.459115 8.459115 ZT12-15 14.761425 12.456199999999999 17.06665 ZT16-19 14.316400000000002 14.316400000000002 14.316400000000002 ZT20-23 17.636850000000003 17.636850000000003 17.636850000000003