condition mean min max ZT0-3 6.4730525 5.83664 7.109465 ZT4-7 7.62233 7.62233 7.62233 ZT8-11 5.91464 5.91464 5.91464 ZT12-15 0 0 0 ZT16-19 8.001675 8.001675 8.001675 ZT20-23 6.95489 6.95489 6.95489