condition mean min max ZT0-3 8.7641895135 7.533535003 9.994844023999999 ZT4-7 4.040484408 2.4063579455 5.6746108705000005 ZT8-11 4.7420701735 4.3944922045000006 5.089648142500001 ZT12-15 4.750976913500001 3.664297639 5.837656188 ZT16-19 12.00951131025 10.8776163205 13.1414063 ZT20-23 13.856356055000001 13.152310705000001 14.560401405